Margaret (Jeong-ae, Yun In-ja), a North Korean spy and madam of a cabaret, saves Sin Yeong-cheol(Lee Hyang), who is on the run as a thief under suspicion. In-Ja, who loves him, helps him escape after caring for him and giving him food. One day Margaret happens to meet Yeong-cheol, who works as a manual laborer on the wharf. She buys him clothes and shoes and confesses her love for him. Later they are happy as lovers, but she is uncomfortable remembering herself as a spy. One night after they had made love, she happens to see his ID card which identifies him as an anti-espionage lieutenant. Shocked, she then tries to avoid him and he is heartbroken. One day he receives a piece of intelligence that a spy will contact a woman. He secretly follows the spy, which later ends up in a gun fight. Margaret, who had been waiting for the spy sees Yeong-cheol, and hides herself.Park, the head of the spies, uses Margaret to kill Yeong-cheol. She is in dismay, but is obligated to draw his attention, and kill him. Meanwhile, Yeong-cheol discovers her true identity, but decides to die for the woman he loves. Margaret just cannot shoot him, and protects him when someone shoots at him. She gets hit instead. Yeong-cheol finally kills the chief after a long fight. Wounded Margaret wants to die in Yeong-cheol's arms so he shoots her, weeping.