Li Liang (Simon Yam), a middle-aged man with an ordinary appearance, walks on the bustling streets of the downtown. His ordinary appearance cannot attract anyone's attention, but his heart is full of little-known dark secrets. Li Liang came to the police station to surrender. He confessed that he was a serial killer, but his reasons and motives for killing were thought-provoking. For him, killing is not a cruel deprivation of others' lives and the right to survive, but a way to redeem them. At that time, Li Liang's wife was tortured by leukemia and chose to commit suicide in extreme pain. This incident hit Li Liang hard, and he then deliberately paid attention to various suicide news on the Internet. Since suicide will cause desperate people to fall into an endless hell from which they can never be freed, why don't you lend a helping hand to help them? Thinking of this, Li Liang began to act. He accepted commissions from all kinds of trapped people and took them across the boundary between life and death. He never thought about where such an extremely perverse approach would lead himself and others...