Heyes and Curry have two problems. The brother of their sponsor, Lom Trevors, has confessed to murder and sent to Yuma Prison. An editor of a newspaper in Tombstone, the victim had been a crooked saloon owner he'd exposed and had in turn been threatened by the man. He was shot in the back.
The boys want to help the Sheriff clear his brother.
In Tombstone they pose as reporters and, with Johnny Behan's help, cast doubt on Sam Trevors' confession. They're sure he's covering for someone, likely a woman.
They are also recognized by an old comrade and forced to help rob a Wells Fargo shipment of a payroll when the gang kidnaps THE woman after they figure out her identity.
Now they have to rescue her and find the real killer, all while avoiding the train robbery that will end their bid for a pardon.