In 1943, Wei Xianjiang, who was fighting in the Northeast, was recalled to Chongqing to carry out the task of assassinating the "boss". The young man assigned to assist him under surveillance was Shen Changqing, who had returned from studying in the United States. Shen Changqing is young and energetic, and is the best in shooting. He was not convinced by Wei Xianjiang at first, but he was converted by Wei Xianjiang through hardships and hardships. But after unmasking Wei Xianjiang, facing his partner who had lived and died together, he could no longer hold a gun against him... If the undercover has love, it must be with lies, if the hero has love, it must be stained with blood.