The top killer of the Nelson family, Jack Quin, a family of three, accidentally discovers that Duowei, a teenager who has helped him, and secretly shows mercy to his subordinates. Duowei, who doesn't know the truth, takes refuge in Jiekun, hoping that Jiekun will fulfill his promise to teach himself and avenge his adoptive parents! Jackie Kun becomes Duowei's teacher, and the ruthless killer meets an innocent and beautiful boy like a white rabbit, but gradually touches his heart? When will the hidden secret be revealed, and how will the two face it?