When a train is robbed, Longarm’s got a one-track mind…You mess with the mail, you mess with Longarm. Two mail bags have been stolen from a Union Pacific train—and the postal worker guarding them has a bullet hole in his skull. Since there are no signs of forced entry, Deputy U.S. Marshal Custis Long can only assume the postal agent was in cahoots with the train robbers, who then double-crossed their inside man and made his wife a widow. Teaming up with a ravishing U. S. Treasury agent by the name of Beatrice Raven, Longarm is determined to track down the train robbers and the missing mail bags. But the thieves have other ideas—like delivering the lawman to an early grave…