The Sleuth of St. James's Square, by Melville Davisson Post (epub/Kindle)

Once considered by many to be the greatest American mystery writer of all time, Melville Davisson Post (1869-1930) has begun to fall into undeserved obscurity in the near century since his death. The Sleuth of St. James’s Square, first published as a book in 1920, aptly demonstrates his strengths, and it makes a good place to start for anyone encountering Post’s work for the first time. This volumes includes 16 mystery stories, each connected—if sometimes tangentially—to Sir Henry Marquis, head of the Criminal Investigation Department of Scotland Yard, who is called upon to solve some of the strangest and most puzzling cases in Britain. It starts with a locked-room mystery and ends in Scotland, at a house by a Loch where more is going on than meets the eye. A first-rate collection.