Detective Dan O'Grady's best friend, Captain Street, is unable to find the killer of his friend, and asks Mr. Wong, a Chinese detective, to assist him in the case. The murdered detective had been working on a smuggling case. As Mr. Wong investigates various suspects including a jewelry store operator and a nightclub owner, three more murders occur. With the help of reporter Bobby Logan, Wong and Captain Street finally catch the murderer, Forbes, at the last moment.