Volume 70 (1969) in the Agatha Christie Collection. Limited edition of 1000 copies world wide. At a Halloween party Joyce -- a hostile thirteen-year-old -- boasts that she once witnessed a murder. When no-one believes her she storms off home. But within hours her body is found still in the house drowned in an apple-bobbing tub. That night Hercule Poirot is called in to find the evil presence. But first he must establish whether he is looking for a murderer or a double-murderer...