After a bank is robbed in Union, Missouri, the Pinkerton Detective Agency arrives on scene to track down the thieves. In a flash of insight, agency director William Pinkerton pairs two very different detectives to handle the investigation. On one hand is the young George Dougherty, a bookish office detective who has been studying the latest scientific investigative techniques, and on the other is veteran field detective Charles Schumacher, a hard-charging man of action who’s dodged a few bullets in his day. As George meticulously combs the crime scene for clues, Charles rushes to hunt down the unknown suspect. When they attempt to arrest the Missouri Kid for the robbery, Charles is killed in a gunbattle, and George is left to finish the job and avenge his partner’s death. Some years later, gunfighter-turned-reporter Bat Masterson meets up with George, who is now the NYPD Deputy Commissioner, to find out how the Missouri Kid was finally brought to justice.