After robbing a train of $30,000, Irish outlaw Sean Devlin and his bandits interrupt their get-away to rob a stagecoach. While defending the coach, Matt's son-in-law Josh is shot in the leg, a traveling barbed wire salesman Davis Healy is hit in the arm, and a widowed mother of two, Hannah Miller, is mortally wounded. Three passing cowboys intercede and chase the Devlin gang off. The stage stops at Dillon's ranch to help the wounded since it is closer than town. Hannah dies at Matt's ranch house. Her eldest boy Lucas (age 15) sneaks away in the middle of the night to seek revenge with his father's gun belt and deputy's badge. In the morning, Matt heads out after the boy to try to keep him from being killed. Healy, despite his wound, insists on joining the pursuit, causing Matt to question Healy's motives. Meanwhile back on the ranch, the younger orphaned boy Martin has been left in Beth's care, but he refuses to eat or speak. Beth tries to coax him out of mourning. During the film, it is revealed that just like Lucas, Matt's father, a
Texas Ranger, was killed in the line of duty as a lawman. This detail was never mentioned in the entire 20-year course of the television series. ==Cast==