The Three-Body Problem—Cixin Liu

I read this 2008 novel, published in English in 2015, in about five sections, I wrote in detail about what I had read after each section. Spoiler alert: If you read this running commentary, you will find out everything that happens in the book as I read it.]

7th February 2021
Part I: Chapters 1-3—Silent Spring
This seems to be a kind of prologue to the main action of the novel, because I see that Part II opens ‘40-plus years later.’ Part I introduces us to Ye Wenjie, the daughter of a physics academic murdered by over-zealous Red Army Guards—in fact, adolescent girls in uniform—in the Cultural Revolution in 1967. A basic error of this ideology at this time was that if a scientific theory was developed within a capitalist society, it must be based on bourgeois misconceptions. Anyone in China favouring such theories must, ipso facto, be a traitor to the people and must, at least, be barred from working in science. It led to the mass exile of many and, two years later, Ye Wenjie finds herself working in a corps of loggers. She hates the destruction of centuries-old trees, but everyone else is fine with it. Until…

…a journalist arrives, and she notices that he is as wistful about the doomed trees as she is. He ends up lending her a copy of Silent Spring, one of the first texts to have received wide publicity for its author’s concern for how human activity was interfering with local ecologies. A few days later, when she returns the book to him—it’s a good job she can read English as well as he can, an ability I’m sure will come in useful later—he shows her a letter he is writing to the high-ups in Beijing. She’s enthralled by it, and offers to make a neat copy of his scribbled text. Oh dear—the next thing she hears about it is that it’s brought a lot of trouble down on her. The journalist—spit—has denounced her, pretending that the content of the letter is all her work.

Things get pretty heated pretty quickly. A party high-up, well-known for her good-cop way of getting wrong-headed miscreants to see the error of their ways, comes to Ye Wenjie’s chilly cell to try to get her to sign a letter, already signed by many others, bearing (false) witness to meetings her father had with various people. She refuses to sign a document referring to meetings she knew nothing of, and the smiling apparatchik smilingly pours cold water all over her, and all over her bedclothes. This is midwinter in the mountains near the border with Mongolia and, much later that night, Ye Wenjie is falling into frozen unconsciousness.

Luckily, she is rescued. She wakes up, still feeling terrible, and realises she’s in a helicopter. She recognises one of the uniformed men as Yang Weining, a former postgraduate student of her father’s, and she is astonished. He tells her they are going to a scientific installation we’ve already heard of, described as an object of mystery in the area and surrounded by rumours. This is the enormous Radar Peak, and he is offering her the opportunity to work there, and build on the knowledge of physics she gained in her father’s department. But if she does, he tells her, she will spend the rest of her life there.

A couple of other things. The facility has a parabolic dish directed into space, and is well-known locally for sometimes emitting some kind of electromagnetic pulses that are so powerful that birds fall dead from the sky anywhere nearby. Meanwhile, at the heart of Ye Wenjie’s contemplation of the terrible things she has seen being perpetrated by humanity is the paradox of the nature of evil. Are humankind, and whatever constitutes evil, essentially different aspects of the same thing? She thinks of how the ocean and an iceberg are made of the same element. ‘That the iceberg seems separate is only because it is in a different form. It was impossible to expect a moral awakening from humankind itself,’ what is required will be ‘a force outside the human race.’ In earlier centuries, this might lead to the conclusion that religion must play essential part. In a science fiction novel, especially one in which human beings appear to be transmitting something important into space, maybe the answer lies out there somewhere….

19th February
Chapters 4-11—the first half of Part II, Three-Body
Things have got very strange. It’s 40 years later, and Liu seems to have had science following a mostly conventional-sounding trajectory in the meantime. It’s a version of the present day that readers in 2008 would have recognised, although some developments are fictional. It doesn’t matter one way or the other because Wang Miao, the new main protagonist, has suddenly been wrenched into a reality in which impossible things are suddenly happening. He’s been co-opted by a coalition of international agaencies with strong links to the military, investigating the suicides of cutting-edge theoretical physicists, all members of a group known as Frontiers of Science. He is shown the suicide note of one of them, and it seems to suggest that all physics ever studied is wrong, or irrelevant, or otherwise defunct. Such a discovery would be upsetting if one’s life’s work were unceremoniously trashed, but why on earth have so many resorted to suicide?

This is China, and the translator offers notes and occasional pointers as to the different expectations of a Chinese readership. Wang is certainly a more unashamedly male protagonist than a western readership might expect a middle-class scientist to be. He has a wife and son, but he seems to treat them as though they hardly exist. After the first chapter or so of Part II, Wang is rarely at home and his family has hardly been mentioned again. The man he considers his nemesis is Shi Quiang, a hardboiled cop universally referred to as ‘Da Shi,’ Big Shi, who could be from a John Woo movie. It’s only to prove Da Shi wrong that Wang takes on the assignment to try to find out what’s happening to the scientists. In fact, Da Shi quickly becomes his minder and his ally—his persona is awful, but he’s very, very good at his job. When things get too weird for Wang, he’s there to pick him up and, perhaps inevitably, take him out for a drink. Or a lot of drinks.

Wang quickly reaches a point beyond amazement at the way, as soon as he agrees to be involved, external forces appear to be directed at him personally in impossible ways. It’s as though… what? As though he’s been selected by other elements than any that we humans can perceive. The suicide note he reads—this is quite early on—is that of Yang Dong, a woman Wang had never met, but had seen outside a world-renowned particle-accelerator project she had overseen. She had had an extraordinary effect on him at the time. He is an amateur photographer, good enough to have had work published, and as soon as he has an image of her in a picture he took outside her project, all his other photographs seem soulless to him. He had always wondered what the problem was, and he had suddenly realised that what they lacked wasn’t soul, but her.

So, he agrees to do what he’s been invited to do, to see if he, a non-specialist—he’s into the applied science of nano-technology—can find out what it is that’s freaking out the top theoreticians. The next day is the weekend, a chance for him to spend some time with the family. Only joking—he goes out taking black-and-white photographs with his old-school pre-digital Leica. We might wonder why Liu specifies this, but it becomes clear when Wang develops the films that evening. Every single frame, impossibly, is stamped with a string of numbers. After some frantic messing about, he realises a) that this is impossible, b) only if he takes the pictures, on whatever camera, do the numbers appear—it doesn’t happen when he gets his wife and son to try—and c) it’s a countdown, in hours, from the moment he took the first picture. Zero is in 1200 hours from then, i.e. 50 days.

He realises from the insomnia and stress that this new reality brings about for him that the other scientists must have gone through something similar. He goes to see Ding Yi, a man who not only worked with Yang Dong, the woman who had affected Wang so much, but had been in a relationship with her. After an elaborate demonstration involving them both moving a pool-table around the flat, it’s easy to prove that the laws of physics are constant in different places. Cue a simple ball and it will always go into the pocket. (Yes, I know.) But he tells Wang this hasn’t been happening in the particle-colliders. There are three of these worldwide, and they all come up with impossibly variable results. It would be, among other alternatives, like hitting a ball and having it bounce off impossibly, then fly straight through the wall and off into outer space.

He goes to see Shen Yufei, a top woman scientist, and discovers that she is in the middle of a VR game, complete with full-body V-suit. This is a science-fiction thing, a suit that can reproduce all the sensations of the VR reality coming through the headset. Da Shi had advised him always to look at web addresses, and he does so: Coming out of the game, the woman clearly knows what he’s talking about when he describes what’s happening to him, and she (or it might be somebody else later) warns him the countdown will only stop if he stops the work he’s doing. Wang is perplexed. What has his little applied specialism to do with high-powered theoretical physics? Why would anyone, or anything, be interested in the field he’s working in? But by now, he’s used to things not making any sense. So is the reader… which I don’t necessarily mean as a criticism. There’s something dreamlike about this novel, and we’re not even in the game yet.

We will be soon. Wang checks in at the big experimental facility he runs, manufacturing ultra-thin carbon filaments, and by now the countdown is everywhere. He can’t stop it in his vision either by closing his eyes or looking at the brightest possible object. Just as they had on the photographic negatives, the numbers adapt their brightness according to the immediate background, so that nothing obscures them…. As it happens, his top technicians tell him they really, really need to stop the machines and do some maintenance work. To everyone’s surprise—he’s usually obsessive about not losing a moment—Wang tells them to do it, whenever they like. Why not now?—and the numbers in his vision immediately fade and disappear. He looks tired, they tell him, why not take some time off? So he leaves, via a room where they keep their V-suit. Or suits—I forget how common these bits of kit are in Liu’s 2008.

The game, when Wang enters it while wearing the V-suit, is as all-involving as the cyberspace alternative reality of Neuromancer, William Gibson’s 1984 game-changer. (I don’t read masses of science fiction, but I assume it quickly became a trope that characters can pop into and out of a different reality through a magical digital interface. It was being satirised as early as 1988 in Red Dwarf’s ‘Better Than Life’ episode.) Days can pass, with one or other of the players being able to fast-forward if necessary, then weeks and months… and Wang finds he’s deep inside an impossible-seeming puzzle. Everything else seems impossible, so why not the alternative reality of the game too, in which everybody is trying to come up with a way to predict when the next ‘stable period’ on a strange planet will be, in between the many chaotic periods during which sunrise and sunset seem entirely unpredictable. If the sunrise doesn’t happen, it’s the start of a chaotic period.

On his first visit, the passing of the ‘flying stars’ seems to be important, especially when all three of them arrive at the same time. Are these the three bodies? Is the rising of the sun, or the movement of the earth, dependent on the interaction of these celestial bodies? It seems a promising line of inquiry, and one man thinks he’s got it. Wang has joined him on his journey to see the current King—there’s a mythologised Chinese history in there—and, at his instigation, the dehydrated human beings kept in granary-like stores are re-hydrated. And guess what. His prediction is wrong, and everybody who can do so dehydrates again as quickly as possible. Failure of ‘Civilisation No. 127,’ or whatever it is. (I should check, not that it really matters.)

Wang leaves the game and, no doubt to the surprise of absolutely nobody reading this, little or no time seems to have passed. He goes to visit a 60-something-year-old woman, the mother of Yang Dong, the suicide who had interested Wang so much. Pool-table man had urgently suggested he do this, both because she needs the company and because she has interesting things to say. Reader, she’s Ye Wenjie from Part 1, physics veteran but no longer involved, and not under threat from whichever forces are trying to stop science in its tracks. Now, she’s more likely to be playing with her grandchildren than delving into issues of theoretical physics… which is what she’s doing when Wang arrives. She tells him—or is it Pool-table man on another visit? My memory isn’t what it used to be—that at a certain time the next night, for four hours, the universe will flicker for him.

I’m pretty sure it’s Pool-table man, who is able to arrange for Wang to visit the local radio telescope at the right time. The astronomer there warns him how boring it is to observe the background radiation of the universe, because it takes millions of years to change in any respect. When Wang says he wants to observe it anyway, at 1.00 in the morning, he tells him there’ll be nothing to see. But we know better and, at 1.00, suddenly there’s a big change. The astronomer knows it must be a malfunction and checks in with the other observatories. They’ve all got the same reading. The universe is telling Wang that the reality everybody knows about is wrong. And anybody else who happens to be watching can see it too.

Liu decides we need more proof. The astronomer tells Wang that visual headsets exist that enable viewers to see cosmic radiation at a wavelength perceptible to the human eye. These are at the local planetarium—the translator’s note didn’t mention anything about narrative plausibility, but let’s not worry about that when the reality of the universe is in question—and, after a call to the caretaker or whoever, Wang gets one of them. And it’s true. He can see the universe pulsing, and he knows it’s just for him. You couldn’t make it up.

Time to get back into the game. Eons have passed, and the pyramid-like building shielding the then king from the impossible heat and cold all those millennia ago is now looking very, very old. The top has been altered, so there is a flat area and, having climbed the staircase that hadn’t been there the last time, Wang meets a new player. He tells Wang he has spent centuries building a mechanical model of this strange universe, and his explanation is bonkers. Stars aren’t objects, but holes in a celestial sphere. The sun—ditto. A machine representing this in all its complexity, including the ability to expand and contract, could not possibly be built… but this man has built it, and he is confident enough to be able to predict not only that a stable era is about to begin, but that it will last for a certain number of years—and he seems to be right. For several days, the sun rises and sets, and humanity decides it’s time to rehydrate. But you’ll never guess what…

No, I mean it. When the sun rises it’s so huge it fills the eastern horizon, and burning animals are racing towards them. In the course of a day, everything is burnt to a crisp. Before he leaves, Wang notices that his own hands are burning torches but, luckily, not really. Meanwhile he finds out by way of a message in the sky that this isn’t the end for humanity, and the game is still on. He’s also found out that another game ended when the sun rose as normal, then simply shrank to nothing, disappearing in the sky in the middle of the day. Why on earth, he wonders—or, if he doesn’t, the reader does—would anybody play a game in which the rules change all the time? It’s worse than Calvinball—which, I notice, is a name recognised by my spellchecker. How gratifying.

Enough for now? Other things are happening, such as projects based on ecologically sustainable methods seem to be somehow finding favour with forces beyond human understanding…. And we remember Part 1, in which Ye Wenjie, the early proponent of exactly this, who also mused on whether humanity might be indistinguishable from the very notion of evil itself, was working on a project to send huge pulses of something out into the cosmos. Forty years later, is something in the cosmos responding? Has humanity been found wanting, and its wrongheadedness subject to some urgent consciousness-raising? Whatever, I’ve just reached a chapter in which Ye Wenjie, not having to look after the grandchildren at this moment, has agreed to tell Wang what they were up to on that mountaintop all those years ago.

20th February
Chapters 12-20—the second half of Part II
I mentioned how dream-like things seem, even when Wang isn’t in the Three-Body game. It carries on like that, but not necessarily in the same way. Like, some chapters after Wang has heard what Ye Wenjie has to tell him—I’ll come back to that—he’s being told a different story, by the husband of Shen Yufei, the woman he first saw in the V-suit near the start of all this. This man, Wei Cheng, is an accidental mathematical genius, in that he’s never sought to become such a thing, but once happened upon a problem that he’s been seeking a solution to ever since. It’s—guess. It was a mind-game he invented to send himself to sleep, not knowing that it’s exercised mathematicians for centuries, and he’s come as close as anyone to discovering where the solution might lie. He knows, for instance, that the necessary calculations can’t be done without computing power greater than any available. And what are the chances that Da Shi should bring him and Wang together at just this moment?

It’s a thought that occurs to Wang himself. Part of Wei Cheng’s story itself involved an extraordinary coincidence, because he had been seeking peace and quiet in a remote Buddhist monastery when a tourist who happened to be a top theoretical physicist had spotted the charred remains of his rough calculations on a bonfire. She was Shen Yufei, of course, and she knows she must nurture his genius. She takes him away from the monastery to work with some of the best computers available, and some of these are very good indeed—which is why he knows none of them is good enough. But that isn’t what Wang is thinking about. ‘Have there been any … supernatural signs?’ It’s as though everything in the real world is happening according to some plan. ‘Wang’s night had been filled with coincidences: he had been called in to discuss the three-body problem with Wei Cheng immediately after he solved the Three Body game. And now Xu was telling him she was monitoring the game.’

But I need to go back, to before Wang’s third (and most successful) attempt at the game. Which, of course, he’s too quick to believe he’s solved. Ye Wenjie tells him, at some length, how Radar Peak—real name Red Coast—was what we suspected. She hadn’t suspected it herself because she was fed misinformation for a long time, as she worked her way up the technical hierarchy. But its purpose was to jump on what the Chinese saw as the bandwagon of attracting the attention of extraterrestrials. Over the years, it became clear what a failure it was, the signals vanishingly weak compared to what was needed and nothing ever coming into their receivers but cosmic background noise. After the place was eventually closed, she spent most of her adult life as a university teacher, convinced that extraterrestrial life almost certainly does not exist.

Is this a smokescreen? Much of her story is about the way she believed for a long time she was working on a microwave weapon aimed at the imperialists’ satellites, fed misinformation in private briefings that were really elaborate charades. She ended up marrying one of the men responsible, Yang Weining, who she had thought was uneasy that she was learning too much. That was all part of the elaborate game. As she is telling the story to Wang, he hasn’t yet discovered that the world of the three-body game is based on a real planet, with extraterrestrial inhabitants. Some of its features really exist, he is told, including—and this is Wang’s literally game-changing hypothesis in his third visit—the fact that it is in a system with three suns. Their movements are unpredictable, and the game is all about devising ways to predict when periods of stability will begin, and how long they will last.

The weirdness, both inside the game and out of it, by no means ends there. After his hypothesis, which makes him an instant star in the game, he is back to a reality in which the famous mathematician is being protected by Da Shi because his wife, the famous Shen Yufei, has been shot at home by Pan Han, associate of both her and her husband and deeply interested in the recent inexplicable phenomena. He, like Ye Wenjie all those years ago, is interested in ecological matters, and we wonder if there’s a link we’re not being told about. But why on earth is he shooting people? This is the event that has brought Wang and the mathematician together, and… it isn’t clear whether events in the game are now influencing events outside, or vice versa, or neither of these. Whatever, the things Wang is learning, especially concerning the three-body problem, make events in the game comprehensible to him.

Inside the game, each time Wang encounters a new civilisation, it has progressed to a point that equates to a later historical period on Earth. His explanation of why three suns would have such a catastrophic effect only makes sense to the other characters because the planet now has Newtonian physics and calculus—in fact, Newton is there, and Wang first meets him in a sword-fight with Leibniz over the authorship of calculus. How we laughed. By the time he enters for the fourth time, gate theory is available, demonstrating that simple binary choices can lead to complex outcomes. It’s the precursor of computer science, of course, but this is an age without technology. Anachronistically but conveniently, the Chinese ‘First Emperor’ is on the throne, and he is able to provide 30 million men, arrayed in a square with sides six kilometres long, who become a living motherboard. I said it was getting weird.

It works, far more successfully than it would in reality—outside the game, another player has demonstrated, through an experiment with only 100 people, how slow and prone to error such a system would be in reality—but it’s all in vain. Months of processing by the 30 million men lead to an outcome that is almost immediately proved wrong. The three suns unexpectedly rise together—it’s a tri-solar syzygy, and everything on the planet is lifted from its surface by their combined gravity. Wang and the others, like everything else, find themselves hurtling into the nearest sun. It’s a good job it’s only a game.

To fast-forward. Explanations outside the game—some of them at a ‘meet-up’ held by the game co-ordinator, who is none other than Pan Han—make it clear that such calculations are a waste of time. Solutions can be found to specific alignments, velocities and vectors, but there is never going to be a fix for the inhabitants of the planet, now helpfully referred to as Trisolaris. And there’s another pressing issue. History informs the Trisolarians that there used to be twelve planets, and that theirs is the only one remaining. What happens from time to time is that a sun comes so close it either splits the planet in two to create, over eons, a new moon—or it swallows it entirely. In fact, there’s a new moon by the time Wang enters for the fifth and last time—and there’s also Einstein. But he’s having to busk for small change, because nobody’s listening to him any more. The Trisolarians have had a new idea….

Rather than wait for their planet to be swallowed up like all the others, as is totally inevitable, they are going to send out an expedition to the nearest habitable planet. Wang sees their one thousand ships, arrayed in formation in the night sky above the heads of all the millions of inhabitants left to manage as normal, and he sees them leaving. They travel at one-tenth of the speed of light, so it will take decades to reach Earth, something like four light-years away. Because, reader, that’s where they appear to be going.

21st February
The first five pages of Chapter 21 in Part III—Sunset for Humanity
Yes, it was a smokescreen. Ye Wenjie did not lose interest in the idea of extraterrestrials, or in her long-held belief in the inherent baseness of humanity. Wang has been invited to another meet-up, but instead of seven people in a coffee bar, this one is a meeting of 300 in the shell of an old factory. These people know all about the game, all about Trisolaris—and a lot more. They are the Earth-Trisolaris Organisation, the ETO, the people who are attempting to bring about a worldwide loss of faith in science. Their project has met with some success. But there are factions, the Adventists and the Redemptionists, presumably those who want to wipe Earth clean of humanity, and those who imagine a future in which mankind can be redeemed through close contact with an extraterrestrial culture.

Pan Han is standing on a table, robustly defending his action in killing Shen Yufei, a member he saw as letting down their cause. He had gone to the house to shoot her husband Wei Cheng who, he says, was in danger of solving the three-body problem and ruining their plans. If all of it sounds like a perverse mirror-image of a religious cult, that must be deliberate on Cixin Liu’s part. Earlier, Wei Cheng had talked of how he had once discovered his wife praying or meditating, and ‘the Lord’ was an important part of this rite. The rebels also talk about their Lord… and they also eagerly await their commander, who will be able to decide if Pan Han behaved within the proper parameters. When she arrives, I can’t be alone in having been entirely unsurprised by the shock revelation: ‘the commander-in-chief of the Earth-Trisolaris rebels, Ye Wenjie, walked steadily into the crowd.’

For a moment, I was tempted to believe Trisolaris to be a hoax perpetrated by Ye Wenjie and others, in order to persuade enough people to join an anti-progress action group. But if so, how to account for the countdown numbers appearing on celluloid film and in plain sight? How to make the universe shimmer, or whatever? How to make subatomic particles behave in impossible ways in the accelerators? Unless it’s all a Matrix-style delusion…. But I can’t imagine an Earth-based technology that could bring it about. Maybe we are to believe in the truth of extraterrestrial influence and technology but, surely, we don’t have to believe in a thousand spaceships heading our way. What is this, Independence Day? Or could it be a variation on the hoax perpetrated by the so-called Ozymandias in Watchmen, which purported to be an invasion by aliens in order to bring about an end to nuclear self-destruction?

We’ll see.

23rd February
Chapters 21-29—the first half of Part III, Sunset for Humanity
It seems we have to believe that this is definitely not an elaborate hoax perpetrated by Ye and her desperate enviro-warriors. In the rest of Chapter 21, Pan Han is unceremoniously dispatched, and now Wang is feeling in the spotlight. His nanotechnology research could lead to a super-light material that would be just perfect for a space-elevator, exactly what would be needed in order to build orbiting defences against those pesky Trisolarians. Ah. At the point I’ve reached, it’s been revealed that they won’t be here for 400-odd years—plenty of time both to build a defence and to make Earth not worth the saving anyway. So, Wang’s project has been specifically targeted to deal with the immediate threat of the first… but, as he says, somebody else will develop it soon enough. Which is why, Ye tells him, they’re spending so much time and energy on trying to stop science in its tracks.

It’s in Part III that Liu makes the novel’s main theme absolutely central again. We know about it from Part I, the first signs of environmental awareness in Carson’s Silent Spring of 1962. Liu is writing in the first decade of the 21st Century, when many believed that humanity had done far too much damage for it to be reversed. As this last section of the novel progresses, it becomes more and more a given that this is the truth of it. The ETO might be a dangerous cult, but the question being asked is, are they any more dangerous than the rest of us? Sometimes, Ye and the others seem to hold human lives as of negligible importance. When Wang askes her about her daughter’s death, it takes a lot to detect any reaction at all. ‘Wang noticed that her eyes dimmed almost imperceptibly. But she then resumed the conversation.’

With Pan Han out of the way, Liu can focus on the back-story to all of this, which he does by having Ye start telling the true story of what went on at Red Coast Base. A lot of her followers don’t know this, so it’s a good excuse for Liu to have her tell it. And it turns out she’d been telling the truth about the weakness of the radio pulse they were sending. What she’d missed out the first time was one of those ‘discoveries’ that are useful for moving things on: the sun has inner reflective qualities that turn it into a giant radio amplifier. Who would have thought it? It explains why, eight or nine years after the ‘Hello, universe’ message was first sent, a reply comes. Which, luckily, only she sees in the middle of the night. It’s highly negative, purporting to come from a rare pacifist on a warlike planet, repeating many times that no more messages should be sent, or there’ll be trouble.

She’s only able to understand the sun-amplifier thing when she notices an American’s research in a journal she happens upon, and… and so on. Reader, she decides not to take the advice of the extraterrestrial and, in secret, she sends a ‘Please invade us, we’re making a mess of everything’ message. Which is the vital first step, but a long way from where things have got to something like 30 years later. Liu has a lot more back-story to get through—and there are also things happening in the present-day time-line. Like, Da Shi has come and broken up the party whilst also managing to prevent the detonation of a mini atom-bomb the group keeps handy in case of just such an emergency. His move involves clever bluffs and feints, just like in an action movie. And Ye is arrested.

Luckily, the police want to know about the next bit of the story, which is how did she end up murdering not only her boss at Red Coast, but also her own husband? She’s happy to tell it. Her boss, who turns out to be both self-serving and ambitious, knows about the message from Alpha Centauri—for, reader, that’s where we’re talking about—and plans to cement his own reputation on the findings. This is no good for Ye’s project, so she does a bit of sabotage to force him into lowering himself on a rope over the cliff-edge on the mountaintop. (I’m not making this up.) Just as she’s about to cut the rope with her self-designed make-it-look-like-wear-and-tear hacksaw rig, her husband climbs down the same rope too, to help him. What to do?

The cause is bigger than everything else, she decides… so she cuts the rope, and the water in the stream below the rocks turns red. Lui likes these little details. He also likes to bring in a whole raft of accidental plot developments to make the weird things that are going on seem as though they somehow might just happen. Only joking—most of it is preposterous. Like, years later, when Ye is a professor at her father’s old university, she discovers the most convenient possible ally while out scouting for a site for her new radio telescope. He’s Mike Evans, a committed American environmentalist planting trees in the middle of nowhere, following the kind of deforestation we know about. Interesting, but no help—until he becomes the main beneficiary in his father’s will a few years later. He’s now worth four-and-a-half billion.

Liu has him explain that the legacy must be a sop to his father’s conscience, because his brothers get peanuts by comparison. He, the father, was the oil billionaire whose fixation on providing human comforts at the expense of any species that gets in the way—he says this explicitly, like a kind of mission statement—brought about his son’s environmental idealism. Whatever, once Mike Evans has used his own money to verify Ye’s Trisolaris story he’s willing to bankroll a new organisation, as he tells her a few years later on the converted oil-tanker that’s now his base of scientific operations. The ETO is born, with enough financial backup to develop, over time, a worldwide VR game through which the strange world and culture of the Trisolarians can be made known to many of the right sort of people. Not just anybody can get to grips with what it’s about, and many leave the game early. But the ones who are left, a self-selecting bunch, are likely to be the right sort.

There’s more back-story. The organisation thrives, but splits into the factions we know about. The Redemptionists really do treat the Trisolarian culture as a kind of religious ideal, with ‘the Lord’ at its centre. Meanwhile, we remember the warning that Ye had received in that first reply from Trisolaris all those years ago. The ETO knows about this, but they’re so evangelical about things they’re OK with it. The Adventists don’t care about humanity at all, and the Redemptionists seem to decide that there’s no harm in hoping that the cultures can live harmoniously—even if the role of humans is only to serve.

A couple of final things. By a weird coincidence, on the very day she murdered her husband and boss, Ye had discovered she was pregnant with the child who would grow up to be Yang Dong. As a new mother, she becomes much more involved than before with the local people, living with them when the baby is tiny and needing more sustenance than Ye can provide. And Ye discovers, for the first time since the traumatic events of the Cultural Revolution, that she can connect with people. She even sets up a classroom for the children—a perfect introduction to the world of teaching she will move into when her work at Red Coast comes to an end. Dedicated teacher or fanatic?

Maybe both. Liu does his best to present her as a fully-rounded human being but, for her, everything comes second to the great cause.

25th February
Chapters 30-35—the second half of Part III, to the end
The subtitle of Part III is Sunset for Humanity, and that’s what Wang and the other are contemplating near the end of the novel. There appears to be no solution to the disastrous consequences of Ye’s decision all those years ago to reply to a message that was telling her not to. In 400-odd years’ time, there will be an Independence Day-style invasion, and the Trisolarians have sabotaged the future of scientific developments sufficiently, they think, to ensure that it will be a walkover. In the penultimate chapter, having done what they can to undermine the Adventist faction of the ETO and consequently discovered what the Trisolarians are up to, Wang and Ding Yi, Pool-table man, are drinking themselves into a stupor. To the Trisolarians, they remind each other, they are nothing but bugs. But Da Shi comes along to shake their ideas up. He drives them to his home village, where the wheat crop is being devastated by—bugs. Specifically, locusts are stripping the whole crop, and he reminds them that bugs have been here a lot longer than mankind, and were always going to outlast us. Suitably chastened, Wang and Ding pull themselves together. Just as humanity, superior in every way, has never been able to outwit the bugs… etc.

What Liu is doing is setting up the sequels. He’s already sown the seed of an idea with the concept of the space-elevator, and maybe that’s the direction that the sequels will take. The question is, what technology can humanity develop in 400 years despite being stymied in its attempts to make the next leap, into sub-atomic particle physics? Reader, you’ll have to buy The Dark Forest and whatever comes after it.

But meanwhile, I need to rewind to where I left off last time. What is made clear is that the Adventists, led by Mike Evans, are so fixated on saving other species that they are actively seeking an end to the human race. Worse, only they have access to the messages the Trisolarians have been sending, because the receiving station is on Judgment Day, Evans’s converted tanker. Wang meets the international military personnel he first encountered at the beginning of all this, now gathered to seek a solution to the immediate problem: how to find out what kind of threat the Trisolarians pose. The only copy of the text is on the ship, and nobody can think of a way to attack it without those on board having the time to destroy the messages….

What comes next is pure Mission Impossible. None of the military solutions is feasible, because it only takes seconds to destroy a hard drive. Armed raids, missiles, even the new-fangled ball lightning weapon—has Liu just made this up?—takes time to get started. Luckily, Da Shi is there, in all his bad-boy glory. He’s having a great time alienating everybody, even smoking the butt of the American colonel’s Havana cigar and then, to make a point, reaching over to grab the one he’s smoking. (It’s hard to remember this is supposed to be the early 21st Century.) He reminds everyone that Wang’s raw material consists of molecule-wide carbon filaments, apparently infinitely strong and able to cut through anything with no pressure at all. The ship is going to sail through the Panama Canal later in the week, which is lucky. They will be able to set up an invisible barrier of filaments between two tall poles, and… some other details nobody goes into. And, four days later…

…as the ship slowly makes its way through, it encounters the taut filaments. Seen from the bank, nothing seems remarkable as it passes between the poles, until a radar mast suddenly topples. A man on deck is surprised when he’s suddenly in two pieces, plus another two because his hands don’t seem to be attached to his arms any more… and so on. The whole ship passes through, and it’s in 50-centimetre-thick slices. Cue descriptions of the roar of engines cut into pieces while in the middle of their power cycle, the ship veering to one side, and the ear-splitting shriek of sliced plates of metal sliding over each other, starting from the top, as it reaches the bank. It’ll be an interesting scene if they do make the trilogy into the TV film series that’s being planned.

Da Shi has saved the day. Somebody tells him later that he’s done no such thing—they might have taken all the information they need from the ship’s Trisolaris files, but what good will it do anybody? All they prove is that humanity is doomed. Liu spends a lot of pages explaining how, in the decades since they first decided on an invasion, the Trisolarians have used their advanced technology to mess not only with mankind’s science, but mess with its head as well. What they have access to is multi-dimensional quantum physics. Somebody mentions eleven dimensions, and the Trisolarians are pretty good as far as the ninth. Which means, in the Liu universe, they can perform what seem like miracles. It’s an old chestnut to talk about how advanced science looks like magic to those only familiar with more basic levels, and Liu has Ding Li do exactly this for Wang so we don’t forget it. Time for some set-piece science fiction.

How to do it? How to sabotage Earth science, and create miraculous-seeming events, from four light-years away? Answer, send a supercomputer that won’t take 400 years to get there, and will be invisible. (Whoever said it was right about this looking like magic.) The Trisolarian scientists have to go on a huge technological adventure. Using their ability to manipulate matter in multi-dimensional planes, they explain to their ruler—or ‘Princeps’, a figure not unlike the kings in the Three Body game—that every higher dimension occupies a smaller space. Conversely, a single proton from our own dimension can be tweaked so that it is in a higher one, and therefore occupy a far greater area—all the time retaining its original mass.

After some fun and games—their second effort results in an entity that seems to demonstrate its own sentience, and they have to blast it with old-fashioned nuclear weapons from our own Einsteinian dimension—they create what they’re seeking. That single proton is now a hollow sphere big enough to envelop the whole planet. You can imagine the fun Liu has describing how it expands to this size, its perfectly opaque, reflective form showing the Trisolarians first the night sky from the opposite hemisphere of the planet, and then blocking out all the heat and light from space. The scientists, as they knew they would, have brought about a frozen time, like the chaotic periods we all know about. Why have they done this?

Reader, it’s so they can etch on its inner surface every sub-sub-electronic pathway they need to create the most powerful supercomputer their advanced society is capable of. It doesn’t need to be at a microscopic level, because a) it would be impossible to achieve in space and b) it isn’t necessary. Millions of square miles are enough to contain a design that’s big enough to see with the naked eye. Or maybe it isn’t the whole surface, just a section their spaceships can deal with. Whatever. What they will end up with, when they’ve done their clever dimension-tweaking to get it back down to normal, is a proton-sized supercomputer, able to receive instantaneous input from similar protons kept on Trisolaris—sub-atomic particles can do that, wherever they are, as every reader knows who keeps up-to-date with popular science—and intelligent enough to act independently when necessary. And we all know there’s no limit to their speed, so they can appear to be in a huge number of places at once. It’s like multi-tasking in old-school computer science, as somebody helpfully reminds somebody.

I told you it was set-piece science fiction. We’ve had everything from an imaginary world with its imaginary—if predictably familiar—society, to multi-dimensional science that seems just like magic, to… all the rest. In fact, the world-building is sketchy, so that we’re never told how any life at all could evolve under such outlandishly hostile conditions, never mind super-intelligent beings capable of predicting patterns of behaviour on a planet four light-years away. OK, they’ve had some input, but their ability to predict, for instance, religious fanaticism in a race that would probably seem alien in every other way is really stretching credibility. And that trick with the countdown on Wang’s camera film. It’s designed, like the pulsing cosmic background noise and the misbehaving particles, to seem impossible, miraculous—and those clever Trisolarians are pitch-perfect in their stage management.

It’s hokum, obviously. The question is, is it good enough to carry the reader along? It must work for a lot of people—you don’t win a Hugo Award for just any old nonsense. But how good is the world-building, the alien society, the science? Aren’t the Trisolarians just Klingons with a different physical form? In fact, as Wang or somebody else says, the game gives us Trisolarians who look like us, so it’s difficult to imagine them any other way. This feels like a cop-out to me. So does the way that the seriously Green agenda that imbues the early part of the novel simply fades out of sight long before the end. The danger, despite all the right-on talk of the death of species and the deforestation of the planet, comes not from us but, in classic old-school style, from the nasty aliens. As I think I’ve said before—I did, I checked—it really is Independence Day.

Maybe I’m not the right reader. I always say I like science fiction, but I nearly always find myself counting the tropes. But… Liu comes up with a clever solution to a problem he’s set himself. He needs the Trisolarians to be from our nearest star—Alpha Centauri is a three-star cluster, in fact—otherwise there’d be no story. It would be no good if the reply didn’t arrive for centuries. But he also needs to give humanity enough time to develop ways to use Newtonian/Einsteinian physics to tackle far more advanced technology. Unlike locusts, we’re going to have to think our way out of this one, which I guess will happen in the sequels. I might be wrong, but if I’m right it accounts for Liu having the Trisolarians only travelling to Earth at an average of one-hundredth the speed of light. Cue descriptions of a drive system that has to harvest particles of antimatter as it goes along, thus spending most of the journey just coasting.

It’s a small thing, but it appealed to me that Liu needs a culture that can achieve mind-boggling technological feats, but can only haul itself around space at the speed of a Model T Ford. It’s the one time he subverts the genre. OK, it’s not much—I wanted the whole alien invasion schtick to be a hoax perpetrated by Green activists—but it made me smile.