The Stooges are janitors in a doctor's office working the night shift. The usual antics occur, first with Moe getting an electrical shock down his pants, leading to a cossack dance. Then, Curly gets his head wedged inside a fish bowl, containing a live fish. Though Moe and Larry eventually slide the bowl off, Curly starts to feel the swallowed fish tickling his insides. Moe manages to fish the aquatic critter out of Curly.
Outside, a crook is shot in the arm while trying to make a getaway after a robbery. The crooks bring their hurt leader (John Tyrrell) up to the Stooges, thinking the doctor's office is open for business. The boys play doctor and promptly anesthetize the wounded crook with a rubber mallet. Then, the wounded crook slides off the gurney and out the window while the Stooges' back are turned. As luck would have it, the crook lands right into a police car waiting below at street level. The other crooks flee when they see the Stooges mangle the situation, only to be captured by the policemen.
The trio, meanwhile, take cover in a rather spooky storage area, replete with a huge jack-in-the-box, and a scared night watchman (Dudley Dickerson). Curly gets so spooked that he stumbles into a vat of plaster, making him virtually immobile. As a consequence, the poor, ghostly-looking Stooge ends up scaring all involved.