Brett Cassidy, professional gunfighter, has hung up his guns for the peaceful life of a trapper, but one day he receives an urgent letter from a beautiful young widow. The settlers in Lonesome Valley need him. Cheyenne war smoke is rising, and a greedy saloon owner and his hired guns are making life hell for the widow and her friends. Strapping on his guns for one last time, Brett rides to help the homesteaders in their hour of need. But he's alone and faces a stacked deck in the final showdown in the Last Chance Saloon.