Based on David Mamet's Sexual Perversity in Chicago and filled with recognizable Windy City locales, About Last Night is perfectly fixed in place. It's just as definitively fixed in time thanks to the unmistakable mid-'80s fashions of leading lady Demi Moore and the flaccid, soft rock soundtrack, which featured leftovers from John Waite, Sheena Easton, Bob Seger, and John Oates. Despite the dated accoutrements, the story itself stands up as a well-exectued, if familiar, tale of relationship angst full of predictable but satisfying plot twists and occasionally zippy dialogue. Moore shows off the throaty sensuality and doe-eyed vulnerability that had already made her a star while displaying none of the avaricious careerism that would stifle her a decade later. Rob Lowe, meanwhile, works his pretty-boy looks and flashing-eyed charisma for all they're worth. Elizabeth Perkins is wasted as a standard-issue shrew, but Jim Belushi sinks his teeth into the role of a blowhard lothario -- a welcome break from the all-Brat Pack casts of such companion pieces as St. Elmo's Fire. About Last Night is a little plastic, like the decade that spawned it, but, like plastic, it's surprisingly resilient.