Desc: While London Sleeps: Directed by Howard Bretherton, Walter Morosco. With Rin Tin Tin, Helene Costello, Walter Merrill, John Patrick. Rinty is a police-dog (and faithful companion) assigned to a young Scotland Yard police officer who covers the Limehouse district of London. The East India dock in Limehouse is the home of the scum of the world, especially a group known as the Mediterranean Brotherhood. Scotland Yard is looking for a mysterious "ape-man" (The Monk) whose deeds of violence on behalf of the gang-leader of the Brotherhood has put all of London on guard.