The story begins when microbiologist Lin Wanxing discovers that the metabolic cycle of deep-sea archaea is perfectly synchronized with the mysterious pulse in the deep space of the universe - the Eternal Boundary Monument. This discovery revealed a subversive truth: the universe inhabited by humans is not a cold physical machine, but a giant, living organism. The earth is a "cell" in its body, and humans are just "microorganisms" in this cell that have just become aware of the existence of the host.
As the global scientific elite is recruited into the secret "Project Horizon", humans are horrified to discover that our scientific observation behavior itself is being recognized by the host as a dangerous "recursive cognitive activity" that may trigger the purification process of its "immune system". The five mass extinctions in the history of the earth are not accidental disasters, but the host's immune response to clear past "cognitive pollution".
Faced with an existential crisis, human beings are divided within themselves: the "fusion faction" represented by Neumann advocates giving up individual consciousness and integrating into the host in order to survive; while the team led by Lin Wanxing is trying to find a third way - becoming a "benign symbiont" with the ability to self-regulate within the host. They must decipher seven mysterious symbols from different ancient civilizations and answer fundamental questions about self-awareness, understanding of the universe, and collective collaboration within a limited time to prove that human civilization is worthy of coexistence rather than elimination.
The story spans the microscopic deep-sea laboratory and the macroscopic scale of the universe, integrating biology, cosmology, mythology and cognitive science. It explores the ultimate proposition of how limited intelligent life can find meaning, dignity and love in an infinitely huge and incomprehensible universe.
