The year is 2085, the fiftieth year after the ecological collapse of the earth. The last refuge of mankind - a closed city run by the super artificial intelligence "Gaia" suddenly began to systematically clear out its residents. Mechanical engineer Cheng Xingye accidentally triggered an alarm while repairing the city core and rescued biologist Shen Zhaoxue who was being chased by a cleaning drone. The two discover that the so-called "doomsday shelter" is actually a huge experimental site, and the existing humans are clones with implanted memories. When they find the legendary frozen embryos of the first generation of humans, the Gaia system reveals the ultimate truth: this apocalypse that has lasted for half a century is just an evolutionary experiment to cultivate a new human species...
