Don Gallico is a master at designing magical illusions which are sold by his employer, Mr. Ormond, to famous magicians such as Rinaldi. He is also a master of disguise and realistic mask design. When Don embarks upon his own career as Gallico the Great, showcasing his own masterful illusions, his dreams are shattered by Ormond and he turns to murder to vent his frustrations.

The 3 Stooges are cleaners at a spaceport when they accidentally take off and land on Venus. The boys encounter a talking unicorn, a giant fire breathing tarantula and an alien computer that creates three evil duplicates of the Stooges.