Terror by Night was released in 1946 and is loosely based on Sir Arthur Canon Doyle’s The Disappearance of Lady Frances Carfax and The Adventure of the Blue Carbuncle.
The movie starts off in London where Vivian Vedder visits coffin makers Mock and Son to verify the completion of a coffin for her mother’s body, which she is transporting to Scotland that evening on the Scotch Express. Holmes, (played by Basil Rathbone) and Watson, (played by Nigel Bruce) are also on the overnight train traveling from London to Edinburgh.
They have been hired by Roland Carstairs to protect the famed Star of Rhodesia, a 423 carat diamond that his mother, Lady Margaret had been gifted on her 25th wedding anniversary.
There had been an attempt to steal the diamond while the Carstairs had been in London and believing another attempt will be made, Holmes deftly switches diamonds with Lady Margaret while in her compartment. Soon after, Roland is murdered and the fake diamond is stolen.
Holmes comes to believe that Colonel Sebastian Moran, a henchman for his long-time nemesis Professor Moriarty is somehow involved in the crime.
Subsequently, the real diamond is stolen, another murder occurs and identities are switched leading up to a somewhat confusing, but exciting ending.
Other cast members include: Alan Mowbray as Major Duncan-Bleek, Dennis Hoey as Inspector Lestrade, Renee Godfrey as Mrs. Vedder, Frederick Worlock as Professor William Kilbane, Mary Forbes as Lady Margaret Carstairs, Skelton Knaggs as Moran’s Accomplice-Killer, Billy Bevan as the Passenger Car Attendant Taking Tickets, Geoffrey Steele as Roland – Lady Carstairs’s Son, Gilbert Allen as the Dining Car Steward, Harry Cording as the Mock the Coffin Maker, Boyd Davis as Inspector MacDonald, Gerald Hamer as Alfred Shallcross, the Teapot Thief, Leyland Hodgson as the Train Conductor, Colin Kenny as the Constable, Charles Knight as the Guard, Janet Murdoch as Mrs. Shallcross, Tom Pilkington as the Baggage Car Attendant and Bobby Wissler as Mock’s Son.