Gambler "Lucky Lou" Montaine captures the Cartwrights and tries to makes Ben sign a deed turning the Ponderosa over to him.; The Cartwrights trail vanishing cattle to a canyon death trap. During a single dark night, Adam tracks rustlers who devise an ingenious plot to drive cattle into a river and then divert them from the river into a cavern.; When Little Wolf hits a mother bear with an arrow, Hoss has to defend himself armed only with an ax.; The dangers of cattle swimming across rivers in cattle drives.