Agatha Christie - Hercule Poirot 19 - The Double Clue (1922)

The Double Clue is a short story written by Agatha Christie, which was first published in The Sketch in December 1923 in the U.K. The story was published in the U.S. in The Blue Book Magazine in August 1925. It was later gathered as part of the anthology Double Sin and Other Stories published in 1961 by Dodd, Mead and Company in the U.S. In the U.K. the story was not anthologised until it was included in Poirot's Early Cases in 1974. It is the first appearance of the recurrent character Countess Vera Rossakoff.