HUGE SPOILERS for the entire Three Body Problem trilogy contained within!
You have been warned…

Cixin Liu’s final book in the Three Body trilogy, Death’s End, is a marvelous adventure into the deep future of mankind as it grasps for the stars. Though the novel begins relative to our own time (the Crisis Era of the previous novels) the reader quickly realizes that they are reading a time travel novel. The implications of the “hibernation” technology discovered in the previous book begin to unfold, and the novel’s protagonist, Cheng Xin, uses hibernation to skip across dramatic swathes of time, making great ripples in human society with each leap through history. We get to follow Cheng Xin through a breathtaking panorama of human culture as it swings into territories both alien and familiar.
There are so many fantastic chapters in this novel. A woman flash freeze’s a terminally ill man’s brain and launches it into space on the off chance that aliens might revive it. A scientist falls in love with a black hole and falls into it, living forever in a state of infinite free fall (life insurance won’t pay out because he never technically died from our perspective). Aliens attempt to Hunger Games humankind in Australia. There is an incredibly long interlude about a fairy tale that contains the secrets of FTL. Astronauts discover what it is like to view their three dimensional plane from a fourth dimensional perspective. And so on.
My favorite chapters, of course, relate to Trisolaris. Even in this final segment of the story, we get to see so little of Trisolaris and its inhabitants. In this novel, we learn that after Luo Ji successfully deters the Trisolaran invasion, a period of peace and collaboration ensues. Cheng Xin awakens in the Deterrence Era and is taken to see a movie. The film, which won Best Picture at the Oscars, is beautiful to her, depicting a romance between lovers in some medieval Chinese past.
"I love your era," said Cheng Xin. "I'm surprised."
"You'd be even more surprised if you knew the artists behind these films, paintings, and music. They're all Trisolarans from four light-years away." AA laughed uproariously as she observed Cheng Xin's stunned gape.
(136, Tor Books hardcover)
Yes, in the Deterrence Era, Trisolarans have begun to create art and share it with Earth. They are sharing science too– so much science that humanity is overwhelmed and must create international bodies to study it all!
After the creation of deterrence, the World Academy of Sciences--an international organization at the same level as the UN--was founded to receive and digest the scientific and technical information transmitted to Earth from Trisolaris.
People first predicted that Trisolaris would only provide knowledge to Earth in sporadic, disconnected fragments after much pressure, and sprinkle deliberate falsehoods and misleading ideas into what little they chose to share, so the scientists of Earth would have to sift through them carefully for nuggets of truth. But Trisolaris defied those expectations. Within a brief period of time, they systematically transmitted an enormous amount of knowledge. The treasure trove mainly consisted of basic scientific information, including mathematics, physics, cosmology, and molecular biology of Trisolaran life forms, and so on. Every subject was a complete system.
There was so much knowledge, in fact, that it completely overwhelmed the scientific community on Earth. Trisolaris then provided ongoing guidance for the study and absorption of the knowledge. For a while, the whole world resembled a giant university. [...] The Trisolarans even complained multiple times that humanity was absorbing the new knowledge too slowly. The aliens seemed eager for Earth to catch up to Trisolaris in scientific understanding--at least in the basic sciences.
The scenario floored me as a reader. The Dark Forest ends on a note of hope: Luo Ji speaks to a Trisolaran about love and expresses a desire for peace to win out in the universe. Here, we see a vision of a future in which aliens estranged by light years can collaborate with one another.
Humanity is cautious of course and speculates as to why Trisolaris would be so forthcoming in sharing information after nearly going to war with Earth, but Trisolaris provides its own answer:
Their generous gift of knowledge was done out of respect for Earth civilization. They claimed that Trisolaris had received even more benefits from Earth. Human culture gave Trisolaris new eyes, allowed Trisolarans to see deeper meanings in life and civilization and appreciate the beauty of nature and human nature in ways they had not understood. Human culture was widely disseminated on Trisolaris, and was rapidly and profoundly transforming Trisolaran society, leading to multiple revolutions in half a century and changing the social structure and political system on Trisolaris to be similar to Earth's. Human values were accepted and respected in that distant world, and all Trisolarans were in love with human culture.
This information is likely true, even in light of later negatives developments in Human-Trisolaran relations. In the first book, the supreme leader of Trisolaris limits access to cultural information from Earth because of its power to captivate Trisolarans. The original Trisolaran defector that tried to warn Earth against contacting Trisolaris in the first book is eventually freed and allowed to speak to Luo Ji in the second book. That said, just as Earth society is composed of many different types of people, Trisolaran society has its conservatives and its liberals–its hawks and its doves. Pointedly in this chapter, a note is made that, though Trisolaran art shared with Earth readily depicts human subjects… the physical appearance of the Trisolarans themselves and their environment are still not known to humanity.
At the same time, Trisolaris itself remained shrouded in mystery, with almost no details about the world itself being transmitted. The Trisolarans explained this by saying that their own crude native culture was not ready to be shown to humans. Given the vast gap in biology and natural environment between the two worlds, such displays may erect unexpected barriers in the valuable exchange that was taking place.
Humanity was glad to see everything developing in a positive direction. A ray of sunlight lit up this corner of the dark forest.
In light of later events in the book, when this era of collaboration inevitably collapses back into war and genocide, it is easy to see this chapter in a sardonic light. Clearly, Trisolaris was merely flattering Earth society, just as they had tried to manipulate humans with the Three Body game back in the original novel. Trisolaran artists are extremely adept at manipulating humanity, and there is no reason to think that they would stop doing this during the Deterrence Era. By making humanity love Trisolaris through art, culture, and even a cute robot maid that rebrands the terrifying Zophons into a love-able animatronic woman named Zophon, Trisolaris is able to once again lower humanity’s guard over the long term and break the deterrence model established in the previous age.
Yet, I believe that Trisolaris really did respect Earth. Just as Americans opposed to the invasion of Iran were ultimately overridden by their own government’s desire for real politics, I think the hawks in the Trisolaran military were always ready to attack Earth in the event that deterrence failed. When [SPOILERS] happens and the Trisolaran bluff fails, Trisolaris ultimately spares humanity even when it could have wiped us out in an instant out of spite and revenge. Trisolaris keeps tabs on humanity throughout the long years that follow, and when the time comes to say goodbye… Trisolaris returns to help humanity endure to the end of the universe itself. Trisolaris allows us to discover the secrets of FTL! They didn’t have to do that at all, but they do, because we gave them a cultural power to love themselves and others.
Even the greater aliens [giga spoilers LOL] pause when viewing Earth and Trisolaris from a distance. The high dimensional alien, called a “singer,” tasked with destroying any and all civilizations detectable through radio or other short membrane communications, sees the strange pattern of communication between the two worlds and glimpses something of love in it.
Remember when I said that a woman ships a man’s brain into space so aliens will maybe find it and revive it? Well, they do. Of course they do. In a Dark Forest universe where life is so expansive that it competes for resources with life from other stars, there was no possibility that the brain would not be discovered. The Trisolaran finds the brain and succeeds in awakening it. This ultimate act of species exchange has a human being actually living among Trisolarans in one of their ships. This one weird act may have been what allowed humanity ultimately to survive.
So, when Trisolarans refuse to share their own visage with Earth civilization, is it out of a simple, childlike fear of judgement? Throughout the series (even in this book), Trisolaran communications scorn humanity for being “bugs.” And yet, knowing Earth culture and our incredible capacity for hatred and genocide, perhaps Trisolarans, buglike and strange themselves, were not willing to hold that mirror to themselves. They did not want to see hatred reflected in the cultural exchange of their bodies.
Or maybe Cixin Liu is a bastard and didn’t want to give us the satisfaction of truly knowing the Trisolarans. So much excitement from the series comes from the gap in information present between the human perspective and the aliens they communicate with across many millions of miles of space. Perhaps Cixin Liu knew that no description of them could live up to the mystery, nor can a human writer from Earth truly be capable of describing an alien from another world. All we have is comparison to our own culture and our own world that we have never truly stepped more than a few hundred thousand miles from. Spitting distance in the grand scheme of the cosmos.
We do, however, get some information about what Trisolaran culture may have looked like. Near the very end of the book, when Cheng Xin witnesses the dismantling of her bubble universe, readers finally get a look at objects made by Trisolarans explicitly NOT manicured to appeal to a human gaze.
As the rest of the floor tiles were removed, they also revealed more machinery beneath. These were the first objects Cheng Xin and Guan Yifan had seen n the mini-universe that bore obvious signs of being of Trisolaran origin. Like Cheng Xin had suspected, the design of these machines evinced an aesthetic completely different from human ideals. Cheng Xin and Guan Yifan couldn't even tell at first that they were looking at machinery; rather, the objects resembled strange sculptures or natural geologic formations.
(599, Tor Book hardcover)
After three novels worth of build up, I guess it would be difficult to describe the aliens in a satisfying way. Ultimately, the description would probably be undesirable. We get enough information throughout the series to come up with our own idea of what a Trisolaran might look like. They probably look like bugs to us, or something unseemly that we would instinctively detest, just like we appear primitive and bug-like to them. And yet, it is revealed in the first book that they have retinas similar to ours, and so we know that they see what we see. They too are a witness to God’s beautiful creation!

























