'Agent Number Two' Lee Kwok-wai of the resistance troops Red Rattlesnake sets off for Guangzhou to assist Agent Number One in rescuing their comrade Pang Yau-lan from the puppet army. Lee approaches his former lover Lam Ying-tsi, the mistress and trusted aide of the puppet commander Wong Tai-wai, who has fallen prey to the lip service of the beautiful and smart songstress Pak Lai. Following the vandalism of the arsenal, Pak is quick to point the finger of blame at a spy at work. Lam combs their home for clues and finds Lee's recording devices. Furnishing Lee with misleading information, Lam has Lee and associates arrested. Pak appears to their rescue, revealing herself as Agent Number One. The dauntless spy sabotages the enemy's ammunition and communication network, captures the commander before joining her comrades to celebrate a successful withdrawal. (Synopsis based on audiovisual materials)