### Story summary
- **System Awakening**: Chen Mo, an ordinary programmer, accidentally activated the "Doomsday Ark System" on the first day of the disaster and gained the ability to transform an ordinary basement into a shelter.
- **Hard Choice**: Facing his neighbors asking for help, Chen Mo must choose between self-protection and saving others. Each choice will affect the system evaluation and rewards.
- **Test of Humanity**: After rescuing the little girl Lin Xiaoyu, it was discovered that she may carry a special gene that causes biological mutation, and became the target of competition among various forces.
- **The forces are beginning to emerge**: Meet the former special forces soldier Wang Hu and learn that the military has established a survivor base, but there is a dark faction inside that uses mutants as experimental subjects.
- **Fragments of Truth**: Clues obtained through system tasks show that this disaster may not be a natural phenomenon, but a man-made "human screening".
- **Survival Game**: To upgrade the shelter, you need to go out to find materials, cooperate and compete with other survivors, and maintain a balance between morality and survival.
