New Mexico, 1867: Months have passed since hexslinger Chess Pargeter sacrificed himself to restore the town of Bewelcome, once cursed to salt by his former lover, "Reverend" Asher Rook. Now a coalition led by Allan Pinkerton's Detective Agency lays siege to reborn Mayan goddess Ixchel's notorious "Hex City", the one place on earth where hexes can act in consort, and the desert just outside Bewelcome has become the front line in what threatens to become a new Civil War - one in which wild magic and black science clash headlong, producing carnage like nothing the world has ever seen.