When an escaped circus gorilla appears to have gone on a murderous rampage, a threatened attorney calls on the detective trio of Garrity, Harrigan and Mullivan to act as bodyguards. In short order, we discover that there is more to the attorney than meets the eye, and the ape may be innocent after all. When a pretty young heiress faces peril, it’s up to our heroic trio to save the day.

Captain Caveman is the titular hero of the cartoon series of the same name, he is a caveman brought back to life in the modern age who fights crime and injustice with the aid of his band of mainly female friends: he is armed with a large club and is famous for his battle-cry of "CAPTAIN CAVEMAN!".