Dr Nicolas Harper is being buried in an English country churchyard, in a grave beside that of his wife. There is a stranger among the mourners at his funeral, a young woman in a yellow coat. Afterwards, she visits Dr Harper's adult daughter Hilda and his adult son Dunstan, introducing herself as their half-sister Nicky. Hilda, who hated her father, is a recluse who lives in a marshland cottage with her rescue cats. Disturbed but intrigued by Nicky's...