The stooges do a good turn and help a stranger open a safe in what they think is the man's house. Actually the man is a crook and the boys were unwitting accomplices to a robbery. Once they realize what's happened, the stooges go after the bad guy and who's left on the train to Los Vegas. The boys trap the villain and recover the booty.

The stooges apply for job as 'Yard Men' at Scotland Yard, thinking they'll become detectives, but instead wind up as gardeners. When they accidentally see a memo about the theft a famous diamond, the boys decide to go after the crooks. They find the crooks, but Shemp accidentally swallows the diamond which was hidden in a bowl of candy. The bad guys want to cut the diamond out, but the boys foil them with the help of a friendly gorilla.

A murder is committed during the auction of a valuable statue. The prime suspect is Boston Blackie, whose reputation for living on the edge of the law makes him an easy target for the police. When the body disappears, Blackie must find it to prove his innocence.

An undercover agent wrongly punished for murder is paroled to a remote tropical island with a diamond mine slave labor run by a sadistic foreigner.

The Apaches are on the warpath and the Army must defend them. Murphy's mission is to get a shipment of rifles, but it's stolen by greedy white traders with the help of mutinous soldiers