Holmes and Watson board a passenger train bound from London to Edinburgh, to guard the Star of Rhodesia, an enormous diamond worth a fortune belonging to an elderly woman of wealth; but within the first hour of the trip, the woman's son is murdered and the diamond stolen and any of the passengers in their car could be the killer thief.
as Sherlock Holmes
as Dr. John H. Watson
as Major Duncan-Bleek
as Inspector Lestrade
as Vivian Vedder
as Prof. William Kilbane
as Lady Margaret Carstairs
as Sands - Moran's Accomplice
as Conductor Taking Tickets
as Roland Carstairs
as Mrs. Shallcross (uncredited)
as Alf Shallcross (uncredited)
as Senior Conductor (uncredited)
as Mock the Undertaker (uncredited)
as Baggage Car Guard (uncredited)
as "Inspector MacDonald" (uncredited)
as Mock Jr. (uncredited)
as Dining Car Steward (uncredited)
as Elderly gentleman on train station (uncredited)
