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.

"JOHNNY MACK BROWN AT HIS BLAZING, BLASTING BEST!"