Dr. Cream, a plastic surgeon, operates a wax museum featuring figures of infamous criminals as a front for his real business of altering the faces of fugitive criminals. One of these men, Steve McBirney, was convicted by the illustrious detective Charlie Chan and is bent on revenge. After undergoing surgery, McBirney coerces the doctor to lure Chan to the museum on the pretense of participating in a crime solving radio broadcast. Although suspicious of Cream's motives, Chan accepts the invitation, unaware that he is to be electrocuted as he sits in one of Cream's chairs. However, at the last moment, Chan changes seats with Dr. Otto von Brom, another crime expert, and von Brom is murdered. The weapon is not electricity, however, but a poison dart that is blown at him by someone lurking within the museum. The occupants of the museum are unable to call the police because the phone is out of order, and they know that the person who leaves to make the call may be the murderer. As they are sequestered in the museum, terror electrifies the air as the ominous wax dummies appear to come alive. Later, Chan discovers a trap door leading to a secret chamber, where he traces von Brom's murder to Dagan, McBirney's supposedly dead partner who has had his face altered by Cream. After Dagan kills McBirney and attempts to murder Chan, Inspector O'Mathews of the police arrives with his men. Chan then unmasks Dagan as radio broadcaster, Tom Agnew, who killed in order to keep his criminal identity a secret.