 Tired, hungry and disheveled, Jack Summers (Don Barry) and his pal Nevady (Dub Taylor) drift into Trailcross, where the citizens don t like "tramps", so Nevady (unknown to Jack) tells them that his pal is the notorious bandit Arizona Jack, who will shoot on sight anyone who crosses him, and so begins Republic s 1940 version of Ken Maynard s 1933 "Phantom Thunderbolt" even down to the sidekicks (Frank Rice earlier, Dub Taylor here) sharing "Nevady" as a name. Trailcoss, already plagued by internal difficulties, proves more than eager to provide the astonished Jack with free food and lodging while cowering at his every move. A group of Trailcross citizens, led by Judge Wingate (George Cleveland), Joyce Logan (Janet Waldo) and cattle trader Stevens (Carleton Young), are endeavoring to bring the Texas & Western Railroad through town, and striving hard to meet the two requirements; they must share part of the construction cost and must provide reasonable guarantee that Trailcross is a stable and law-abiding community. Mesa City, a nearby town, also wants the railroad and has hired paid killers, led by Red Mathews (Edmund Cobb), another recycled name from "Phantom Thunderbolt", to keep Trailcross in a state of disorder so that Mesa City will be chosen. Plus, Stevens, seemingly working in the interests of Trailcross, is in reality an extensive land-holder in Mesa City and the "brains" behind the outlaw activities of Mathews and his henchmen. One of the latter, Spike Hudkins (Rex Lease), comes out on the short end of an encounter with Jack, and the impressed townspeople, still thinking Jack is a bad man, decide to fight fire with fire and offer him the job as their renegade fireman. Jack accepts, and before long has convinced the citizens, and Joyce in paticular, that their initial concept of him was wrong. He is hired as Marshal and sets out to rid Trailcross of the Mathews  gang.