Loose in London

The Bowery Boys--Slip, Sach, Bobby, Whitey & Chuck--start their own exterminating service, and get a job which takes them to a spooky old abandoned mansion in the middle of the night. Meeting up with pal Gabe and his new French bride, the boys are tormented by mad scientists who try to convince them the place is haunted and then kidnap Sach in order to place his brain inside a gorilla.

In order to be able to get the names of winning horses at the track, Sach agrees to sell his soul to the devil.

Slip invites his cousin Jimmy to stay with his family after he is released from prison. However, Jimmy soon gets mixed up with an auto-theft ring.

Slip, Sach, Bobby, Whitey and Chuck unsuccessfully try to sell a dilapidated car to a street cleaner for a fabulous amount, so they can get enough money to save Louie's Malt Shop. Sidewalk photographer Cathy Smith snaps a pictures of three bank robbers as they are fleeing a robbery but when the Bowery Boys and Cathy realize that Sach is also in the photograph, they break into the photo lab to destroy the negative, which might make the police think Sach was involved in the robbery.

Slip, Sach and the rest of the Bowery Boys enter a haunted house, where they engage in slapstick with a gorilla, a robot and a vampire

The Bowery Boys head west to clear Louie of an old murder charge that he had killed his gold-mine partner. Sach has the map to the gold mine painted on his back, and Blackjack McCoy has him kidnapped by Indian Joe. Gabe poses as a dangerous gunman, the Klondike Kid, while Slip is in charge of all the remaining loose ends.

Slip gets fired from his job at a construction company for decking his boss. His sister, who got him a job at the company, is angry with him. Slip manages to get a job with the District Attorney serving warrants, as does Sach. Through his job, Slip finds out that all is not quite kosher at his old construction company, and that his sister may be in danger.

A ghost helps the Bowery Boys capture a gang of crooks led by a mad doctor.

When Sach eats too much sugar, he goes into a trance whereby he's able to predict the future. Slip tries to make some money off of Sach by using him as a fortune teller in a carnival, until a mad scientist kidnaps Sach to use him in an intelligence-switching experiment with a monster.

The boys buy a uranium mine out west, but when they get there they find that it's pretty much worthless. However, the local badmen are distrustful of these new strangers, and when they mistakenly get the impression that the mine is loaded with uranium, they hatch a scheme to get rid of the boys and take over the mine.

Sach and the gang fool Nazis and a sultan in North Africa.

Sach and the gang baby-sit a bratty TV star.

Slip and the gang foil foes of the exiled, incognito king of Truania.

After being punched in the nose, Sach finds out that he has the ability to read minds. Slip and the gang start up a detective agency try to cash in on Sach's new powers.

The boys get mixed up with a race horse & crooked gamblers

An overambitious shutterbug almost gets his lights put out permanently when he decides to snap a picture of a mob boss.

Sach learns that he has inherited a farm in rural hillbilly country, and when he and the Boys arrive there, they find themselves mixed up with a hillbilly clan named Smith who'll shoot anybody named Jones, plus a gang of bank robbers.

When a cold medicine causes Sach to be able to smell diamonds, he and the rest of the Bowery Boys are induced by a diamond dealer to accompany him to Darkest Africa in search of a legendary cache of them.

The Bowery Boys tangle with Scotland Yard, diamond smugglers and a gem-toting canine during an ocean cruise.

Slip and Sach take the rap for a robbery they did not commit in order to uncover the real robbers, whom they suspect are led by a convict who gives orders to his gang outside via a short-wave radio stashed somewhere in the prison.