When notorious outlaw Bill Doolin escapes from jail, the U.S. Marshals Service springs into action to end his four-year crime spree. Known as the "Three Guardsmen," Deputy U.S. Marshals Heck Thomas, Bill Tilghman, and Chris Madsen have a reputation for always getting their man, but they know it won't be easy with Doolin. Doolin is no ordinary outlaw: as a former member of The Dalton Gang and the mastermind of The Wild Bunch, he has successfully robbed banks, trains, and stagecoaches. After months of tracking Doolin, Heck Thomas is so close he barely stops to eat or sleep. When Thomas and his posse finally corner Doolin, he refuses to surrender, and gunfire is the only way out. Some years later, Bat Masterson, former gunfighter-turned-newspaperman, catches up with Bill Tilghman to hear the real story behind the hunt for the outlaw Bill Doolin.