On the way back to Fort Union after an escort detail, Sergeant Ben Carter and his detachment decide to stop in the town of Trinity to get some rest. Trinity, however, is no rest stop-a lynch mob is threatening the sheriff, who asks for Ben's help-and, a fugitive has escaped into the nearby San Juan Mountains. Ben agrees to help the sheriff maintain order and bring the fugitive in. But the more he learns, the less Ben believes that things are as they seem. Is he on the side of justice, or injustice?