Duke and Bill are rescued from Indians by a stranger. He joins the train which is headed to Fort Chacon. Unknown to them he is an Army officer. Members of the train are offered stolen Army supplies creating a problem for the officer.

With Chris gone Bill is in charge of the train when Barnaby goes overboard in his pranks. After messing with a wagon wheel, Bill orders him to fix it by himself causing Barnaby to break his leg causing a major rift between them.