The Stooges are secret agents working undercover at the home of Professor Sneed (Emil Sitka) and his daughter (Christine McIntyre). Sneed is developing a rocket fuel in secret for the government. Armenian spy Captain Rork (Philip Van Zandt) watches the professor through his front window, with hopes of kidnapping him. Of course, the Armenians capture the Stooges instead, mistaking Larry for the professor. Trouble brews when the Stooges are required to whip up some the fuel, and then download the formula. It does not take long for the Armenians to capture the real Professor Sneed, along with his daughter, and throw them all in jail until the formula is disclosed. Thanks to a shy prison guard (Jock Mahoney) who cannot help but flirt with Sneed's daughter, the group make a quick exit.
- Moe Howard as Moe
- Larry Fine as Larry
- Shemp Howard as Shemp
- Joe Palma as Fake Shemp
- Emil Sitka, as Professor Sneed
- Christine McIntyre, as Professor Sneed daughter
- Philip Van Zandt, as Captain Rork
- Jacques O'Mahoney, as the prison guard
- Shemp Howard had already died, for his last four films (Rumpus in the Harem, Hot Stuff, Scheming Schemers and Commotion on the Ocean), Columbia utilized supporting actor Joe Palma to be Shemp's double. Even though the last four shorts were remakes of earlier Shemp efforts, Palma's services were needed to link what few new scenes were filmed to the older stock footage.
- For Hot Stuff, Palma is seen several times. The first time occurs when the Stooges, disguised in beards, are trolling through office hallways. Moe instructs Shemp to pursue a suspicious looking girl, to which Palma grunts "Right!" He then walks off-camera, allowing Moe and Larry to finish the scene by themselves. This is the only time Palma allowed his face to be seen on-camera. As he was purposely wearing a beard, his face is successfully concealed.
- Later, Palma is seen from the back while the boys are locked in the laboratory. Palma attempts to imitate Shemp's famed cry of "Heep, heep, heep!". Again, Moe directs Shemp, this time to guard the door. Palma obliges, mutters a few additional "Heep, heep, heeps!," and conveniently hides behind the door. This was one of the few times during his tenure as Shemp's double that Palma was required to speak without the aid of dubbing.