Farley Granger wears an unidentified watch

Strangers on a Train (1951) is Alfred Hitchcock's adaptation of Patricia Highsmith's first novel, with a screenplay credited to Raymond Chandler and Czenzi Ormonde after Hitchcock threw out most of Chandler's draft. Farley Granger plays Guy Haines, an amateur tennis star who wants to divorce his wife and marry a senator's daughter. On a train he falls into conversation with Bruno Antony (Robert Walker), who proposes a criss-cross: each man murders the other's problem person, so neither has a motive the police can trace. Guy never agrees. Bruno strangles Guy's wife anyway and spends the rest of the film expecting Guy to hold up the other end of the deal.

The watch turns up early, on that train. Reclining with a newspaper, Guy raises his wrist to check the time, and a watch on a dark strap is plainly there. The film is in black and white and the angle is high, so no maker is legible, and the watch stays unidentified.