THE DISAPPEARANCE OF MR DAVENHEIM - AGATHA CHRISTIE - SHORT STORY - A GUNSTON CLASSIC Over tea, Poirot, Hastings and Japp discuss the mysterious disappearance of the well-known banker, Mr Davenheim. Despite the energetic industry of the investigating officer Inspector Miller, Poirot says "the little grey cells" would solve the case more efficiently. Japp bets five pounds that Poirot cannot solve the case within one week without leaving his flat. Poirot insists that he can do it, provided all the facts are laid before him. First published in a 1923 edition of Sketch Magazine in the UK and in the USA the same year.