This wry, atmospheric procedural spawned by a real mystery would be thorny enough without also being an adaptation. For viewers familiar with the graphic novel by Alan Moore and Eddie Campbell or the literature of speculation that inspired it, the movie, which partly takes the viewpoint of a psychic detective whose opium dreams drive a serial-murder investigation, may provide yet another compelling opportunity to ponder the Whitechapel murders of 1888 and conspiracy theories surrounding a construct called Jack the Ripper. Labyrinthine yet oversimple, the story seems to hide a more provocative one. But perhaps this is the nature of the beast. Directed by Allen and Albert Hughes; with Johnny Depp, Heather Graham, Ian Holm, and Robbie Coltrane. 137 min.