The son of an Army friend is about the join an outlaw gang. Hoppy prevents this and brings the gang to justice.

U.S. Marshals "Nevada Jack" McKenzie and "Sandy" Hopkins, working undercover, investigate a plot to rob a widow and her daughter of a mine which they know to be filled with gold-laden ore, but the widow believes it has played out. A hermit, hanging around the mine and killing, impartially, anyone who enters the mine, impedes the investigation somewhat.

The new teacher is brutally terrorized by the pupils and becomes the laughingstock of town. Then dramatic events occur which give him a chance for redemption.