Uncle Toby had said that there would be castles to explore, with ghosts and things. This helps to cheer up the glum twelve-year old Lovell twins, Tom and Mary, leaving their schools and loving parents to be evacuated to wild Northumbria during World War II. Then the adventure begins. They live with their Aunt Victoria and Uncle Leslie, meet the loveable 'Mrs M', a strange dog called 'Scamp' and, worst, the terrible private tutor, Miss Urquart, from whom they run away to find a mysterious castle seen through an old telescope. Now they are drawn into bizarre supernatural events of a time-warp...