Roy investigates an automobile accident.; Gene investigates a series of murders and comes across a clue. One of the killers has dropped a rope with 13 knots tied in it.; U. S. Marshal Rex Allen helps a sheriff track a bandit that's been terrorizing the counryside.; Uncle Mike tells a story of how BUllet and Trigger help trap a murderer.; Ricky West agrees to help Roy Ketchum train a horse for a race and runs afoul of some crooks who do not want Ketchum's horse to run.; Bill tracks down a couple of outlaws who are robbing travellers who stay at a particular hotel.; Johnny tries to clear a young man accused of killing his uncle.