A Native American legend materializes in Chicago, and Carl discovers it when he investigates the mysterious deaths of two wealthy society matrons who possessed priceless jewels. When the murders increase, Kolchak learns that the force at work is know as The Diablero, a being cursed to roam the Earth in search of valuable gems.

Cast: Darren McGavin, Simon Oakland, Ramon Bieri, Richard Kiel, Alice Ghostley, Victor Jory, Jack Grinnage, David Lewis, Marvin Kaplan, Ruth McDevitt, James Griffith, Dennis McCarthy, Morris Buchanan, Keith Walker, Marilyn Clarke