Boston P.I. Spenser heads west to the rich man's haven of Potshot, Arizona, a former mining town reborn as a paradise for Los Angeles millionaires. This western idyll is being threatened by a local gang of desert rats, misfits, drunks and scavengers the police seem powerless to corral. Led by a charismatic individual known as The Preacher, this motley band of thieves selectively exploits the town, nurturing it as a source of wealth while systematically robbing the residents blind. Enter Spenser, called in to put the group out of business and to establish a police force that can protect the town. Calling together his own cadre of cohorts, Spenser must find a way to beat the gang at their own dangerous game.