Cass Truman has never met a challenge too great and a horse too difficult to ride, until she meets Typhoon. Typhoon, the spirited black Thoroughbred, defies all control and brings her to a place where today and tomorrow meet. Vague and terrifying, this world is also inhabited by a boy who's in danger of becoming a victim of a terrible riding accident. Will she be able to save the boy or is it already too late?