Oregon, 1851. Hermann Kermit Warm, a chemist and aspiring gold prospector, keeps a profitable secret that the Commodore wants to know, so he sends the Sisters brothers, two notorious assassins, to capture him on his way to California.

In order to make Tug Cardwell (William Phipps) sign over his rich gold claim to them, John Avery (Robert Shayne), Gypsy Avery (Veda Ann Borg) and Jackson (Marshall Reed) hire Bob Rankin (Douglas Fowley') to kidnap Tug's sweetheart Jane Whipple (Elaine Riley). Rankin hides Jane and then demands half the mine from the other crooks. Dave Saunders (Tim Holt) and Chito Rafferty (Richard Martin), friends of Tug's, find Jane and taker her to safety. The conspirators then shoot Rankin, capture Tug and force him to take them to his claim. Dave and Chito are close behind.