Hank McHenry and Johnny Marshall work as power company linesmen. Hank is injured in an accident and subsequently promoted to foreman of the gang. Tensions start to show in the road crew as rivalry between Hank and Johnny increases.

Truck drivers Steve Hackett and Bill Purvis are fired from their jobs with the West Coast Trucking company for not using second-gear going down steep grades. Davis, the company vice-president, surprisingly asks them to carry a load of merchandise to Arrowhead and offers a $1000 bonus. He tells them it is a load of lettuce. Several miles out of Los Angelese, they are stopped by a mob of lettuce-farm workers on strike. When the first crate is tossed off the truck, it explodes and the two pals learn their merchandise is a cargo of dynamite. The workers let them proceed and they crash into a car driven by Mary Stevens, whom they had met at a restaurant. She and her dog, "Butch" (played by a Credited dog named Stooge), join them and they deliver their cargo, and learn unscrupulous real-estate operators have jammed the locks on the dam in order to ruin the ranchers and farmers and take over their property.

Aloysius 'Butch' Grogan leads a life of criminal activities motivated to provide for a widow and her child. He's on lookout for a gang of safe crackers when he has to also look after the baby of one of the criminals.

Driven to desperation by his young and extravagant wife, alienist Dr. Emil Brandt has arranged a perfect crime; now he begs the police to lock him up before he can commit it.

A millionaire courts a working-class woman.

After being criticized by the Citizens' League for his inability to cope with a crime wave, Police Captain Haines orders his men in the Homicide Bureau to clean up all their cases, but without violating the constitutional rights of any suspect. Detective Jim Logan is ordered to meet the incoming new-head of the Police Department lab and internal affairs, J.G. Bliss, and takes an instant dislike to her over her attitude toward criminal's rights.

Hattie Leonard sets out to break a criminal gang controlling the dry cleaning business.

A law student poses as a fight promoter to catch a notorious gangster.

A Japanese man claiming to be Mr. Moto, of the International Police, is abducted and murdered soon after disembarking from a ship at Port Said in Egypt. The real Mr. Moto is already in Port Said, investigating a conspiracy against the British and French governments.

Mandrake and his team attempt to prevent "The Wasp" from stealing and using a new Radium invention.