Although the Three Stooges made a lot of comedy shorts for Columbia Pictures, the studio also made many hundreds of comedy shorts during this same era (roughly 1934-1956) with many other comedians, such as Buster Keaton, Harry Langdon, Charley Chase and more. In "You're Next!", Columbia paired Walter Catlett and Monte Collins and put them into a plot like you'd expect from the Stooges.
Slocum and Pruitt have a detective agency. They're called to protect a rich guy (Roscoe Ates) from kidnappers. However, they do nothing to stop it from occurring (since they are idiots) and soon their client is in the hands of a madman who wants to turn him into a gorilla! Later, a gorilla appears and the duo spend most of the film running away and acting scared.
The plot involves a sick guy trying to turn people into gorillas. Do I really need to say more than that?! After all, the idea is totally stupid and the film doesn't even have a single decent laugh.