Purists may complain that the transition from stage to screen can only come at a price that will devalue the original work. It’s a hard case to make with Bent, with playwright Martin Sherman taking screenplay duty as well. The onscreen product may not offer the shared experience of a live performance, but it still captures beautifully and permanently the story of two gay prisoners at Dachau whose love removes them, in a sense, from their hellish captivity. That’s the heart of Bent, but there is more. Before Dachau, before the ”Night of the Long Knives,” audiences are treated to a surreal interpretation of Berlin’s notorious nightlife. Mick Jagger’s drag persona, Greta, singing the haunting torch song, ”Streets of Berlin” – written by Sherman and Phillip Glass – from her trapeze perch is a breathtaking scene all its own. For a nonfiction lesson in the Nazi persecution of gays, the Paragraph 175 documentary is unsurpassed. For a heartbreaking yet uplifting, fictional exploration of humanity’s extremes, however, watch Clive Owens’s Max and Lothaire Bluteau’s Horst fall in love. And bring tissues. With a setting as grim and violent as the Holocaust, Bent remains one of the most wrenching romantic gay movies of all time.