The McCain's good friend Milly is held prisoner, along with young Mark McCain, in her own general store when two gunmen attempt a daring robbery. Knowing that the North Fork Stagecoach will be carrying $50,000 in cash and will be making a stop in North Fork, they plan to use Milly's store as headquarters to ambush the stage and steal the money. Milly's quick thinking alerts Lucas and the Marshal in time to prevent the theft.