A mathematician and computer expert (Bill Bixby, MY FAVORITE MARTIAN) is traveling by train to London when he meets an elderly spinster (Helen Hayes). She confides to him that she suspects there is a cold blooded serial killer in her village masking the killings as accidents and she is on her way to Scotland Yard. But before she can reach Scotland Yard, she is killed in a hit and run accident ... coincidence or not? Based on the 1939 Agatha Christie novel, the film updates the Christie novel for the 1980s but not for the better. The period charm is lost and the computer expert angle (in the novel, he's a retired policeman) is contrived. As directed by Claude Whatham, it becomes fairly obvious who the killer is early in the game. Everyone is seemed to be made a possible suspect except one character which leads one to conclude that that must be the murderer! The acting is adequate. Hayes had perfected these old biddies by this stage of her career and Olivia De Havilland has a nice turn as another old maid. There is an above average underscore by Gerald Fried (PATHS OF GLORY). With Lesley Anne Down as Bixby's romantic interest, Jonathan Pryce, Leigh Lawson, Timothy West and Freddie Jones.