Public Defender Gary Franklin, frustrated by being unable to save criminal Dutch Adams from a death sentence by blaming the slums environment as the cause of Dutch's crimes, enlists the aid of Dutch's sister, Marcia Adams, to get the slum dwellers at appeal for public monies to provide recreational places for the slum kids.
Rancher William Norton refuses to sell his cattle for half price, so saloon owner and gang leader Jim Fletcher, contrary to the orders from his secret boss Willard McGowan, the town banker, has his men rob and beat up Norton. Unknown to anyone, Marion, McGowan's adopted daughter is really the daughter of Norton, who disappeared as a young baby when she and her mother were passengers on a stagecoach held up by McGowan. Chuck Saunders, Norton's foreman, goes after the gang for robbing his boss and eventually uncovers the truth regarding Marion's heritage.
An actress is murdered in the midst of shooting a dance sequence for her latest picture, with Inspector Steve Trent on the case.
A kidnapping, three airplane crashes and several fist-fights adds speed to the plot in which the plans of a new, faster airplane motor invented by brothers Tim and Jerry are stolen and suspicion falls on their office secretary Mary Stuart. But she can pilot an airplane with the best of them and she risks her life to save Tim. And when she gets kidnapped, Jerry regains his lost nerve in rescuing her.
Canadian Mountie Mason is sent south of the border to look for a horse thief with only a watch chain for evidence. He befriends young Andy and when Calhoun hits Andy, Mason and Calhoun fight. In the scuffle Calhoun's watch with the missing chain is dislodged. Mason then sets out to bring in Calhoun and his gang.
The cattle on the Langton Ranch are mysteriously dying and cowhands are disappearing or being shot. Two Langton riders bring a wounded rider they found wounded and hung up in a barbed-wire fence to Sally Langton and report that her father is missing. A lone rider, Jess Ryder, tops a rise and sees a band of men working on some calves in a secluded corral, and he frowns as he sees what Bat Murchinson is doing.