Smoke Tree, Arizona, is a dusty little town where people live in fear. a cutthroat gang of cattle rustlers called the Rock House boys runs roughshod over local ranchers. they steal at will and anyone who fights back ends up full of lead. the US marshal and the town sheriff are either too yellow or too busy fighting each other to do anything about it. thats why ranchers have the Cattlemans Protective association to help them and thats why the association hires men like captain boyd mcmasters to solve its problems. mcmasters has decided that the rock house boys are through and that cattle rustling is finished in smoke tree. he's made his decision now he's gonna enforce it. and onyone who disagrees can take it up with his rifle.