Marshal Johnnie Taggart, posing as an outlaw named "Ace" Braddock, comes to Bannack, Montana to restore law and order. But he is recognized by Kitty, co-owner with Clay Curtwright of the infamous Bull Whip saloon. But "bad-girl" Kitty keeps her mouth shut. When Johnnie's pal Andy reports a stage holdup, Curtwright's henchman, Ben Borden, talks the sheriff and Judge Holden into suspecting Johnnie. Johnnie reveals himself to Judge Holden as a government marshal, and the judge voices his opinion that Curtwright is the leader of the road agents, but voices it in the presence of his granddaughter, Louise Holden.