The stooges are private detectives hired to find a missing girl. The boys disguise as pie salesmen and end up wandering around a mad scientist's mansion, trying to find the girl. The boys confront a gorilla and various other bad guys, before rescuing the girl.
Practical Effects
Gloriously cheap gorilla suit and 3-D gimmicks flying at your face.
Acting
Shemp's panicked wheezing—an underrated art form.

Director
Jules White
Trivia, insights & behind the scenes
This was one of only two Three Stooges shorts shot in 3-D, part of 1953's brief Hollywood 3-D craze. The 'spooks flying at you' gimmick was literally the selling point.
The Jeckyl/Hyde name spelling ('Jeckyl') was intentional to avoid legal issues with the 1931 Fredric March film's rights holders. Classic studio cowardice!