The Man Who Was Nobody - S0.E5

A slick young man buys a jewel with a cheque that bounces. He then disappears and both the police and a secretive lawyer try to find him. The lawyer hires a good-looking woman to track down the missing man and to tell him that "South Africa Smith is coming back" Her search leads her to beatnik cellars, smart, illegal gambling parties and prestigious mews in Chelsea. The missing man's body is later found in the Thames but the case is by no means over.