While London Sleeps is a 1926 Warner Bros. film about a police-dog, Rinty, who helps Scotland Yard defeat a dangerous criminal organisation known as the Mediterranean Brotherhood that operates out of the Limehouse district of London. Walter Morosco wrote the screenplay and the film holds the distinction of being the first of many films directed by Howard Bretherton. The film was one of several created for Rin Tin Tin, a German Shepherd dog used in films during the 1920s and 1930s.