Exceptional film noir double bill opens with "The Scar," with Paul Henreid in a dual role as a sleazy ex-med student and con artist who meets a psychiatrist who, except for a scar on his face, is the crook's double. He launches a twisted plan to takethe doctor's place, only to get caught in his own scheme. With Joan Bennett, Eduard Franz and a young Jack Webb. AKA: "Hollow Triumph." Next, former G.I. Lloyd Bridges crosses the sea to hunt down a wartime girlfriend in London, but joins police onthe trail of a deadly sniper before he can untangle her from mobsters, in "The Limping Man." With Moira Lister, Alan Wheatley. 159 min. total. Standard; Soundtrack: English Dolby Digital mono; bonus TV episode.