Marshal Matt Morgan, a lawman of unwavering moral principles, is devastated when his Native American wife is brutally assaulted and murdered. Evidence points to one of the culprits being the son of his old friend Craig Belden, a powerful and ruthless cattle baron. Determined to bring justice to his wife's killer, Matt travels to the town of Gun Hill with the intention of capturing the younger Belden and returning him to stand trial.

Upon arriving in Gun Hill, Matt encounters resistance from both the townspeople, who are under the control of Craig Belden, and Belden’s loyal henchmen. Knowing that his quest for justice pits him against formidable foes, Matt's resolve is continually tested as tensions rise and loyalty is questioned. As the clock ticks and the final train departure looms, Matt must navigate the perilous landscape of Gun Hill to achieve his mission of justice or die trying.