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

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

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 Whistler, mysterious narrator of the radio series of the same name, “knows many things” for he “walks by night.” This time the unseen whistler knows all about mentally disturbed…