The setting is, as the title and summary imply, a post-apocalyptic doomsday situation. The MC Ruan Xian was a severely disabled scientist who spent his last years alive working on developing an AI--and withholding it from the public, much to his partner Fan Linsong's annoyance, leading to his secret assassination. Following his death, his algorithm is adopted and modified by his research team and, as expected, things go awry. When Ruan Xian's body is resynthesized by a series of happy accidents twelve years later, he finds ruins, mechanical c*ckroaches, and most of the remaining human population being kept in walled enclosures referred to as 'petri dishes'. Super cool already. And it just keeps better with each new 'map' unlocked.

The worldbuilding is probably the most inaccessible part of this novel. There is definitely a lot going on, and the pseudoscience that the author has developed is rather in-depth. If you are easily intimidated by such things (big long terms, biotech, lots of definitions), this may not be the novel for you. But I find the world itself very rigorous--pretty much everything adheres to the established internal logic, and it provides the most stellar backdrop for the themes explored.

Very well done. Ruan Xian is a very interesting character, and for someone with such stunted emotions (him and ML Tang Yibu both, actually), he certainly knows how to carry an emotionally gripping novel. He and ML are both very capable in their own rights--OP by definition, in fact--but they have a very realistic and touching struggle against the world, against each other, and even against themselves. Other than the MC and ML, Yu Le and Ji Xiaoman are also very developed and sympathetic characters. I do wish we got more of both of them strutting their stuff (especially Yu Le!) but, well, it's not their show. Each character has consistent motivations and their development (individually and in concert with one another) makes sense. One of my faves who I wish we got more of is Zhong Qing.

Far and away my favorite aspect of this novel. The author poses several questions through the book, none of which have nice neat answers. Some rather heavyhanded ones are about human existence--what does it mean to be human? How much of a human can we 'replace', Ship of Theseus style, before it becomes something else? Does the soul exist? Etc. The futuristic setting of the novel lends itself to a very meaningful exploration of these themes, and I find myself agreeing with the general message put forth, but there's a different set of ideas far closer to home hidden between the lines.

Throughout the book, governance, surveillance, and incarceration are all very relevant to the conflict and the characters. Most of the protagonists (spoilers ahead)

are undesirable in society for some reason or another, and the world that the Mainbrain promises would have no one like them. Everyone would be healthy and well-adjusted, free of dangerous tendencies and harmful thoughts. Traumatized individuals could have their traumatic memories directly removed. Diseased individuals could have their memories and genetic data ported into an artificially created body shipped back home. But would this be a good thing, necessarily? Should people like Ruan Xian or Tang Yibu have their lives ruined because they could possibly be dangerous?

Furthermore, the author draws several comparisons between the human existence and suffering. In order to prove that he is human, Ruan Xian reveals his scars from self-harm

Although MC never hurt anyone in his life, he was tested as a psychopath as a baby. Therefore, he was always under surveillance. MC had lived his life hiding his true self to be acceptable to society.

ML is actually MC's creation, called NUL-00 and created in 2090.

On November 21, 2095, MC (28 years old) was mu*dered by his research partner, Fan Linsong. FL then wanted to backup ML's data and destroy ML (who was a cybernetic brain without a body at this point). ML mistakenly thought MC was the one who wanted to dispose of him for failing to complete his assignment. ML was able to escape his destruction and proceeded to work towards completing his assignment.

On March 16, 2107, MC's body was restored due to a series of events. MC is then captured by ML. At this time, ML believes MC is an android too. MC and ML did not know each other's real identity when they met. The story progresses with them being in cooperation, becoming attracted, falling in love, but still willing to kill the other if needed through most of the novel. However, the way it unfolds is with mild angst and a good bit of humorous cuteness. We can define ML's love meter for MC by his appetite and willingness to share his precious food with MC. 😂

They journey together with the goal of finding the rebel leader "Ruan Xian", aka Professor Ruan. PR is the clone created by FL to cover up his mu*der of MC. FL and PR had worked together and created ML's little brother, MUL-01 in 2096. MUL-01 took over the world on December 31, 2100. FL and PR were trying to kill it. At the start of the novel, FL had been captured and PR was missing.

SPOILER IN REGARDS TO THE ENDING...

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MC and ML defeat MUL-01. Instead of killing it, they negotiate with MUL-01 to have it observe humanity until it naturally obliterates itself. MUL-01 had taken over the world to prevent humanity's destruction since it considered itself humanity's caretaker. Once humanity is gone, MUL-01 can use its stored data create a new world based on its own design.

MUL-01 agrees and works together with them to reset the world to December 31, 2100.

PR, who has become a brain without a body, becomes data and decides to join MUL-01 in observing the world.

MC and ML live together happily... dating and going on missions to stabilize the reset world.

the one being a sentient AI, the other a memory-preserving physical clone merged with a machine

In stray, Ollie and Nimo become to be heroes. Literally. Through actions, thoughts, personalities...... they become heroes in every sense of the word. But this one is different. No, actually, it's the exact opposite. Really, I can't help but admire how beautifully the two stories were portrayed! 10/10