Loose in London

After Slip is drafted into the Marines, the rest of the gang volunteers so they can be with him. Sach discovers that the colonel knew his father and he is promoted. During a drill that he is putting the rest of the gang through, they find a soldier left for dead on the side of the road. Slip discovers a playing card next to the marine and traces it to Jolly Joe Johnson's gambling house. They suspect that the gambling house is cheating and set out to uncover the proof.

The Bowery Boys find a lamp that has strange magic powers.

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.

A man wins $50,000 in a card game with gamblers, but is soon found dead and the money missing. Slip and Sach find the money near where the body was discovered, and soon find themselves the target of both the police and the gamblers.

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, 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

Slip (Leo Gorcey), Sach (Huntz Hall), Bobby (Bobby Jordan), Whitey (William Benedict) and Chuck (David Gorcey) 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 (Bernard Gorcey) Malt Shop. Sidewalk photographer Cathy Smith (Teala Loring) 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.

Sach is given a post-hypnotic suggestion that turns him into a championship prizefighter.

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.

The Bowery Boys: 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 has entered the Boys' rattletrap car in a souped-up jalopy race, but has no chance of winning until Satch, with the aid of a scientist acquaintance, comes up with a chemical concoction that acts as a super-fuel; but a rival entrant in the race learns of this and tries to get the formula for himself.