The Moabite Cypher: Dr Thorndyke has to decypher a code to stop a plot to assassinate a Russian Grand Duke.
Cast: Barrie Ingham (Doctor Thorndyke), Peter Sallis (Doctor Jervis), Julian Glover (Barton), Derek Smith (Professor Popplebaum), Nicholas Selby (Superintendent Miller), Max Faulkner (Mounted Policeman), Clive Rogers (Victim), Eric McCaine (Inspector Badger), George Innes (Adolf Schonberg), Keith Taylor (Fierce Man), Peter Beton (Mr James), Graham Seed (Porter), Michael Harding (Derek Smith)
Writer: Reginald Collin / Story: R. Austin Freeman / Producer: Jonathan Alwyn / Director: Reginald Collin
Original Airdate: 26 Mar 1973 on ITV
Series: The Rivals Of Sherlock Holmes Season 2 Episode 9