Hallowe'en Party by Agatha Christie

Summary of Hallowe'en Party by Agatha Christie: At a Hallowe'en 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...

My two cents

The setting: a children's halloween party complete with bobbing for apples, looking in the mirror to see your true love, a "real" witch ... and the presence of a well-known writer of mystery stories. A child boasts that she witnessed a murder, and hours later she is drowned. See how a murder committed years ago comes back to haunt a community.

With Christie's characteristic references to Greek mythology of a bevy of characters, a beautiful garden .... and a complicated plot of money and saving beauty for beauty's sake. And Poirot saves the life of yet another just in time!