A deranged artist who may have murdered his wife is investigated by the Whistler.

A mad doctor (Bela Lugosi) and his helpers (John Carradine, George Zucco) lure girls to his lab for brain work, to help his wife.

The discovery of a perfectly preserved caveman prompts a mad scientist to attempt a daring brain transplant.

The Falcon travels to Mexico where he gets involved with murder and a mysterious painting.

A happily married woman sees a psychoanalyst and develops doubts about her husband.