This is a classic effort by members of the famous Detection Club, which included the greatest crime writers of the early 20th century. Authors are listed as: Agatha Christie, Dorothy Sayers, G. K. Chesterton and Certain Other Members of the Detection Club. 1980 Charter, mass market, first time in paperback. First edition, first printing. Excellent condition, with only corners of covers slightly bent. See photos. An ingenious mystery, written a chapter at a time by top authors. Very fun! Introduction by Dorothy Sayers.