Contrary to what's suggested in the Film Center's Gazette, the version of Alfred Hitchcock's 1929 masterpiece being shown is not his first sound picture, but the film that immediately preceded it, his last silent. (Both versions follow the plight of a murderer caught between her blackmailer and her boyfriend, an investigating detective.) For all the experimental interest of the sound version (the first full-length talkie released in England), this recently uncovered silent version, which hasn't been seen anywhere in more than 60 years, is the more fluid and accomplished of the two. Apart from two suspenseful set pieces--an attempted date rape in an artist's studio that ends with the murder of the artist-rapist, and a chase through the British Museum, Hitchcock's first giddy desecration of a national monument--what most impresses here is the masterful movement back and forth between subjective and objective modes of story telling, as well as the pungent uses of diverse London settings. As someone who's always preferred Lang's treatment of serial killers to Hitchcock's, I would opt for this thriller over the much better known The Lodger as Hitchcock's best silent picture, rivaled only by his less characteristic but formally inventive The Ring. A new 35-millimeter print will be shown; David Drazin will provide piano accompaniment. Film Center, Art Institute, Columbus Drive at Jackson, Friday, May 21, 6:00, 443-3737.