Fourteen-year-old Anthony Monday of Hoosac, Minnesota, and his friend Miss Eells, the Hoosac librarian, try to stop an evil wizard from turning the world into an icy wasteland.
Johnny Dixon, Fergie and Professor Childermass comply with a strange will left by the Professor's brother, which requires them to spend the summer at a desolate estate where they encounter a madman bent on destroying the world.
While spending the summer in an old house on a desolate Canadian island, Anthony Monday and Miss Eells discover a chest that can transport them to another world and a maniacal group who are plotting the destruction of people on Earth.
Lewis Barnavelt and Rose Rita Pottinger are faced with a dilemma when their discovery of an unpublished opera score unleashes a wicked sorcerer who plans to rule the world by bringing back the dead.