The Adventure of the Orient Express is a 1965 short story by American author August Derleth. It is one of the later instalments in Derleth's long running series of Sherlock Holmes pastiches about the Holmesian detective Solar Pons and his trusted associate Dr. Lyndon Parker.
This particular story sees Parker, travelling on the Orient Express on a mission from Pons, encountering several thinly disguised versions of prominent crime/thriller protagonists from years prior. These include two unnamed adventurers representing Sapper's Bulldog Drummond and Leslie Charteris' Simon "The Saint" Templar, an ageing spy named Ashenten after W. Somerset Maugham's Ashendon, and finally Hercule Poiret based on Agatha Christie's Hercule Poirot.