Ben and Marian Rolf rent a grand old country mansion as a summer getaway for themselves, their twelve year old son Davey, and Ben's Aunt Elizabeth. They feel they can't turn down the rent deal offered to them by the house's owners, siblings Roz and Arnold Allardyce, despite some reservations. First amongst those reservations, they are to take care of the house on their own, which Ben feels is too big a job, especially for Marian and the interior housekeeping. In Marian's words, the large size of the house is a "waste". And second and perhaps more important amongst those reservations, the Allardyces' aged mother will be staying in her room at the house, the Rolfs who are to provide a tray of food left outside her room three times a day, which Marian vows to take care of on her own, with no other members of the family to go into that isolated wing of the house so as not to disturb Mrs. Allardyce's peace. Upon their arrival at the house for the first day of their stay, they find a note ...