U.S. Deputy Marshal Merlin Fanshaw is out of town on the day George Starkweather and his outlaw band hold up the Cattleman's Bank of Dry Creek. Upon his return, Fanshaw's boss, U.S. Marshal Chance Ridgeway, suggests the deputy volunteer to infiltrate the gang as an undercover agent. Fanshaw hesitates only a moment before agreeing. He and Starkweather have a dark history, and he's eager to bring his old nemesis to justice.

The winter of 1886-87 brings Fanshaw face-to-face with Starkweather, as he becomes a member of the outlaw band. As the bitter winter deepens, so does the danger, and Fanshaw finds himself in more trouble than he ever imagined. Just when he thinks he's played his cards right, Fanshaw lands in jail-charged with murder, while Starkweather roams free. Will a surprising revelation bring retribution to the outlaw leader, or will Deputy Fanshaw be left alone to face a hangman's noose?