Superman and Supergirl must save Smallville, and the world, from the Reverend, a gargantuan scouting probe disguised as a human reverend named Powell, as well as its master, an even larger alien parasite that wishes to unite Earth's inhabitants in perpetual unity.

Darkseid brainwashes Superman into believing he is his adopted son. With Superman under his control, Darkseid sends him to Earth to decimate its military force.