Hal Barwood and Matthew Robbins, who wrote Steven Spielberg’s Sugarland Express and together made the fine, virtually unseen Corvette Summer, are the authors of this superbly atmospheric sword-and-sorcery tale. Peter MacNicol stars as the archetypal sorcerer’s apprentice; his mentor is Ralph Richardson, in a wonderfully weird performance. The film excels as a visual exercise, as a study in adolescent psychology, and even as astute political analysis (it’s the dragon who holds the fiefdom together).