In the year 2130, the surface of the earth has become a radioactive wasteland. Humanity huddles in the last giant underground city - "Noah's Ark" to survive. The "Titan Heart" energy core that maintains the city's operation is failing at an irreversible rate and is expected to be completely extinguished within three months. By then, millions of residents will be exposed to deadly radiation and severe cold, and the fire of human civilization will be completely extinguished. This is the countdown threat that hangs over all survivors, the Sword of Damocles hanging above their heads.
Long Si was once the chief maintenance engineer of "Titan Heart" and the only person who mastered its core repair technology. However, when the core first experienced abnormal fluctuations, she was accused of "deliberate sabotage" and "treason". The evidence was conclusive and she could not defend herself. Key components of her mechanical prosthesis were forcibly removed and turned into scrap metal. She was deprived of all honors and exiled to the "Forgotten Land" where the radiation on the surface of the earth is strongest. This is a double desperate situation of environmental and social oppression. A technical genius is deprived of all possibilities to display his talents.
The moment when civilization collapses does not come from the outside, but from the inside. On the seventh day when Long Si was struggling to survive on the surface, a cold voice was forcibly connected to the consciousness of all survivors around the world (including surface exiles): the doomsday survival system was activated.
