Wizard and Glass, the fourth episode in King's white-hot Dark Tower series, is a sci-fi/fantasy novel that contains a post-apocalyptic Western love story twice as long. It begins with the series' star, world-weary Roland, and his world-hopping posse (an ex-junkie, a child, a plucky woman in a wheelchair, and a talking dog-like pet named Oy the Bumbler) trapped aboard a runaway train. The train is a psychotic multiple personality that intends to commit suicide with them at 800 m.p.h.--unless Roland and pals can outwit it in a riddling contest.