In the world of the "Seven-Day Natural Disaster" of endless reincarnation, Chen Jin is a destroyer who only wants to die, and has exhausted all humanity in hundreds of restarts. Shen Guang is an observer with zero memory, carrying the mission of repairing the world, and instinctively pursues his figure. When he deliberately stepped into the magma, she disobeyed instructions and saved him for the first time; when she was about to die saving others, his cold heart felt stinging for the first time. This is the ultimate game of "destruction" and "salvation" in the countdown to doomsday - he thought he was teasing an innocent experimental subject, but he didn't know that she was his only and final coordinate in the long darkness.