In this story told mostly through letters, children's book author, I. B. Grumply, gets more than he bargained for when he rents a quiet place to write for the summer.
Twelve-year-old Seymour Hope and his ghostly "mother" Olive go to Scotland to claim a castle inherited from Ignatius Grumply's punster uncle, Ian, but while they tend an aged tortoise and face an unscrupulous developer, Iggie deals with Ian's ghost and aninept insurance agent.