Half owner of the T.M. ranch, Buck Trent walks away from it to continue his journey to Mexico. He stops at Fort Huachuca to report the whereabouts of Ezra Boggs and is blackmailed into infiltrating Ezra's band of Comancheros. A non-stop western ending in a nowhere town called Concho Verde which lies in the mouth of Diablo Canyon where only the invited reach the town alive.