Adding a dose of whodunit mystery to classic B-movie western fare, this Guinn 'Big Boy' Williams vehicle is certainly unique. Reclusive rancher John Duncan (Charles K. French) is about to draw up his will, which includes directions to the $50,000 he's hidden somewhere in the vicinity, when a masked intruder breaks in and shoots him in the heart. Duncan's son Big Boy, who comes to town in response to an urgent summons his father issued just before his death, is faced with the task of finding the