The Little PeopleJohn Christopher
Bridget's inheritance from an Irish relative is a a crumbling house and tower on the edge of a bog in County Mayo. When she decides to run it as a hotel, she and her guests discover the previous inhabitants: seven miniature people inhabiting a room of dollhouses. But why do they only speak German, and what mysterious powers do they possess?
Christoper Samuel Youd, a.k.a. John Christopher (1922-2012), was a British science fiction author. He is best known for The Tripods trilogy.