After a grueling cattle drive to the north where Andy Quinn's Pa, Pecos, was shot in the back by rustlers, the cattle are finally sold and Pecos is with Doc Burns in the offices of Doctor Smith, trying to get the bullet out of Pecos' back. That leaves Andy and his pal, Hasty, free in a wild cow town. Because all the other cow punchers are getting drunk, Hasty talks Andy into having a beer in a local saloon. Here they run across what seems to be a young boy who swipes change from a drunk. Andy isn't fooled, however, and, with Hasty in tow, goes after the culprit.
It soon turns out Andy is right. The change thief is a girl named Jo An who helps her Grandpa out at his local stable while he's sleeping off last night's drinking. She takes money from drunks because he doesn't pay her. And when she gets out of her boy clothes, she's darn pretty. Andy is smitten. He and Hasty agree to come back the next day and see her.
When they show up at the stable, Jo An's Grandpa has passed away. She's alone and in a lot of trouble. Hasty agrees to watch the stable while Andy takes her to Doc Burns for help with what she thinks is her Grandpa's will. In the meantime, Andy has an altercation with the fellow she took money from in the saloon. It turns out he's the real crook. His gang is planning to rob a train. Meanwhile, Andy's Pa isn't getting any better. Andy decides to help Jo until Pa can travel back to their ranch. He doesn't know the deadly peril this simple choice will open him up to.