A mysterious alien descends upon the town of Heart's Desire and offers to share his extraordinary powers with four outlaws - Jake Miller, his brother Ben and their partners in crime, Frank and J.D. Kelton. Taking on the human form of his first victim, a mild-mannered preacher, the alien follows the quartet to the Miller's hometown and gives both sets of brothers strange new powers that make them virtually invincible. As the Keltons kick off a crime spree by destroying all opposition with blasts of pure energy, Jake struggles with his divided loyalties, between love for his family and his childhood sweetheart Miriam -- and the terrible question: who is this mysterious stranger and why has he given the outlaws such deadly powers?