Lewis and Uncle Jonathan have travelled to England to visit family at Barnavelt Manor, much to Lewis's delight - he hasn't visited family outside of America before!
Lewis becomes friends with the housekeeper's son, Bertie, and as the two boys explore the manor's garden maze, Lewis accidentally unleashes demonic forces that summon the ghost of an evil wizard adamant on destroying his entire family.
Can Lewis fight the maniacal wizard, or will all the Barnavelts perish?