Tower at the End of the World - The House With a Clock in Its Walls 9, Paperback/John Bellairs

When Lewis, his uncle Jonathan, and their friends Rose Rita and Mrs Zimmermann take a trip to a small town near Lake Superior, they expect a pleasant holiday. Instead, they find themselves facing the ghastly Ishmael Izard, son of the fiendish creator of the Doomsday clock that was once hidden in the walls of Uncle Jonathan's house.