Death's End (Chinese: 死神永生) is a science fiction novel by the Chinese writer Liu Cixin. It is the third novel in the trilogy titled Remembrance of Earth’s Past, following the Hugo Award-winning novel The Three-Body Problem and The Dark Forest. The original Chinese version was published in 2010, while the English version, translated by Ken Liu, was published on 20 September 2016.
Death’s End begins with a flashback to the siege of Constantinople when a 4-dimensional fragment enters the Earth. A woman named Helena accidentally enters the fragment (located at the top of a minaret), allowing her to manipulate 3-dimensional objects and appear to do magic. To get attention, she steals a golden chalice, which, with many other treasures, had been sealed into an extremely well secured treasure chamber, using massive stone blocks comparable to those used to build the pyramids, and the entrance sealed with a similarly sized boulder lashed to the walls with thick iron bars. Not only that, she was never seen, and accurately states that there would be some fresh grapes placed on top of the treasure pile. Upon hearing this, The emperor, Constantine XI, summons her, and orders Helena to prove her magic by taking the head of a Turkish prisoner by sundown; Helena brings back the brain of the prisoner without appearing there physically, and the corpse of the prisoner is found intact. Constantine then orders Helena to assassinate the Sultan Mehmed II. However, at that moment, the Earth leaves behind the 4-dimensional fragment, and Helena fails to perform her magic; she is then executed, and Constantinople falls the day after the night of the new moon.
The story then shifts to Yang Dong, just before her suicide. She asks a question to a man who has green glasses: What if life never occurred on Earth? A computer simulation results in an oxygenless, barren planet, and Green Glasses states that life is a force that, with time, can do many things; for example, a colony of ants could move a mountain, given time. Yang Dong thanks Green Glasses, and leaves, thinking about her discovery that her mother Ye Wenjie had communicated with Trisolaris, who occupied the Centauri star system, and Yang Dong is troubled by the question: "Is nature really natural?"
The main character of the story is Cheng Xin, a rocket scientist who enters hibernation in the Crisis Era and then is awakened repeatedly in different eras. Following the events of The Dark Forest, the Trisolarans are held at bay by the threat of broadcast by Luo Ji. Luo Ji’s post is that of the “Swordholder,” the person who can threaten the two worlds by revealing the coordinates of Trisolaris and Earth. Following an election, Luo Ji's responsibilities are transferred to Cheng Xin, whom the Trisolarans knew would be unable to release the broadcast message. The Trisolarans destroy humankind's large space fleet, as well as the gravitational broadcast stations. One spaceship that escaped the destruction manages to transmit the location of Trisolaris, and eventually their home world is destroyed in a dark-forest "photoid" attack. Humanity spends centuries defending against a similar photoid attack, only to be destroyed by a "dual-vector foil" attack that collapses the space of the solar system into two dimensions. A few humans escape, including Cheng Xin, in light-speed spacecraft. With the assistance of a Trisolaran robot, they are able to enter another universe, only to return to the original universe.
The story line is divided into eight eras:
Common Era: The period before humans learned of the existence of Trisolaran civilization. The book starts during the Fall of Constantinople with the story of a prostitute seemingly able to retrieve objects and even human organs without penetrating their enclosures. Offering her services to Constantine XI She is thus tasked with killing Mehmed II, but mysteriously loses her powers the day before Constantinople falls.The Crisis Era (present era - 2208 AD) is the time period after Trisolaris and the Trisolarans become widely known and Sophons begin to block all scientific progress. The story of this era starts with Yang Dong, the daughter of Ye Wenjie, having uncovered her mother's conspiracy with Trisolaris and losing hope in life; she has a conversation with a colleague that suggests to her that civilization can change the state of the universe. The plot then moves to Yun Tianming, who suffers from terminal cancer. Receiving an unexpected sum of money, Yun Tianming secretly buys a star, DX3906, for scientist Cheng Xin, whom he has loved since college. Cheng Xin is working on a project called the Staircase Program, using nuclear pulse propulsion to send a spacecraft containing a human to the Trisolaran Fleet to potentially gather information. After being forced to lower the maximum weight multiple times, they realize that they will only be able to send a brain, and will not be able to preserve it - the host will have to be dead. They must hope that a Trisolaran ship intercepting the brain will be able to restore the brain to life. The government sends out applications to be the host of the brain. Yun Tianming, about to be euthanized, is con about the program and terminates the euthanasia. He eventually becomes the final choice, and, on death, his brain is sent on an intercepting course towards the Trisolaran fleet. Cheng Xin's superior, Thomas Wade, reveals that Yun Tianming was the one who gave her DX3906, triggering a persistent guilt in her that the Trisolarans will be able to clone his body when they intercept his brain. Cheng Xin enters hibernation with her assistant Ai AA.The Deterrence Era describes the age after Luo Ji deters the Trisolarans with the threat of mutually-assured destruction by broadcasting the location of their home world. Luo Ji becomes the first Swordholder, the individual endowed with the sole responsibility for initiating broadcast. Earth Federation recalls the two human ships that survived the Doomsday Battle. Upon their return, the crew of Bronze Age is charged with crimes against humanity for destroying other ships in the fleet, but the captain manages to warn Blue Space not to return to Earth. Earth Federation and Trisolaris together send the ship Gravity to pursue Blue Space。 Two Droplets are also sent as assurance to Trisolaris because Gravity has the ability to broadcast the location of Trisolaris. Earth and Trisolaris lose contact with Gravity as the pursuit reaches the Oort cloud; the crew of Gravity begin seeing patches of space disappear or see the crew of Blue Space on their own ship, which they rationalize as hallucinations. Cheng Xin and Ai AA awaken from hibernation and sell the planets of DX 3906 to Earth but retain ownership of the star; with the money from this transaction, Cheng Xin starts the Halo company, managed by AA. They meet Sophon, a Trisolaran android who provides a diplomatic and communicative link between Earth and Trisolaris. Cheng Xin is elected the next Swordholder as humanity find her unintimidating image reassuring. Trisolaris predict Cheng Xin's inability to broadcast their location and begin an invasion, destroying all broadcasting stations, and simultaneously the Droplets attack Gravity and Blue Space.The Post-Deterrence Era describes the age when Trisolarans prepare Earth for Trisolaran settlement. Within a year, nearly all of humanity is forced onto Australia under the threat of Droplet attacks, nearly leading to genocide. Cheng Xin and Ai AA live under the protection of Fraisse, an Australian aboriginal leader, and Sophon, who still respects them, and thus do not suffer the material shortages of other human refugees. The Droplet attacks miss the ships, as they are incapacitated by the crew of Blue Space. The two human ships congregate and vote to broadcast the location of Trisolaris in retaliation for the attack. Blue Space crew members explain that they have found patches of 4-dimensional space that 3-dimensional beings can enter, through which they manipulated the Droplets, by breaking the strong-interaction forces that held them together. They find a large patch of 4-dimensional space and are able to communicate with an AI aboard an abandoned ship in this space, which claims that 4-dimensional space is shrinking and that many 4-dimensional civilizations are leaving ships as tombs in the patches that are left.The Broadcast Era begins after humanity broadcasts the location of Trisolaris from the Oort cloud. Trisolaris is destroyed by a photoid attack, and Trisolarans cease their planned colonization of Earth on the assumption that Earth will soon be destroyed as well. Humans, including Cheng Xin, return to the other continents. Before leaving, Sophon tells Cheng Xin that she can speak to Yun Tianming, who has indeed been cloned. Their conversation is meant to be personal and is monitored for intelligence that Trisolarans do not want to be divulged, however Yun Tianming tells Cheng Xin three interconnected fairy tales. Cheng Xin understands that these are coded messages, and humanity is able to decode most of the content. In anticipation of a similar photoid attack on Earth, humans choose between building space cities shielded by the outer planets, isolating the solar system in a "Black Domain" with reduced light speed, and developing light-speed ships to escape. Cheng Xin enters hibernation after turning ownership of her company to Wade, but asks that she be woken if his research threatens humanity.In the Bunker Era, most humans living on Earth move to space cities in the shadow of Jupiter and other gas giants, having chosen to use them as shields. Research on light-speed ships is halted due to fear of escapism. Cheng Xin is woken as Wade has threatened armed resistance should the government prevent them from researching light-speed travel. Cheng Xin urges him to surrender to avoid bloodshed and again enters hibernation. She is woken upon a dark-forest attack warning, where human fleets discovered a square projectile targeted at Earth, which begins to collapse space into two dimensions, and which can only be escaped with an escape velocity of the speed of light. Cheng Xin and Ai AA are given a mission to fling selected human artifacts into space so as to preserve them in two dimensions unadulterated by nearby matter.The Galaxy Era focuses on the lives of humans who were able to escape in a single secretly-built light-speed ship, and the humans who lived in the generation-ships that were launched during the Broadcast Era.
