In England, an eccentric police inspector, an earnest test pilot and a spunky female reporter team up to solve the mystery of a series of test aircraft which have disappeared without a trace while over the ocean on their maiden flights; unaware, as they are, that a spy ring has been shooting the planes down with a ray machine hidden aboard a salvage vessel which is on hand to haul the downed aircraft aboard, crews and all.

In this film's version of the story, four of the Reno Brothers are corrupt robbers and killers while a fifth, Clint is a respected Indiana farmer. A sister, Laura, who has inherited the family home, serves the outlaw brothers as a housekeeper and cook. One brother is killed when they go after a bank, the men of the town appear to have been waiting for them…