The story takes place in a parallel reality where a gray fog catastrophe ravages the world. The gray fog corrodes human bodies, transforming people into fog-mutated creatures and destroying modern civilization. In his previous life, Jiang Yan survived for three years in the gray fog apocalypse, repeatedly risking his life to protect his teammates, Lu Zhou and Wen Wan. However, both coveted Jiang Yan's unique source-tracing perception ability. On the eve of an approaching high-level fog tide, they cruelly stripped him of his innate ability and killed him. Consumed by boundless hatred, Jiang Yan is reborn 72 hours before the gray fog apocalypse begins. Back from the dead, he sets out to uncover the truth behind the catastrophe, one step at a time!