Marilyn Monroe's first bona fide starring role came in Don't Bother to Knock, a taut, stripped-down film noir. She plays a recently institutionalised, none-too-stable babysitter, awkwardly tending a little girl in a Manhattan hotel. Richard Widmark, jilted by the songbird (Anne Bancroft) in the hotel lounge ("The female race is always cheesing up my life", he pouts), puts the make on the lonely blonde in room 809, to his regret. The picture benefits by not being a "Marilyn" movie, but just a good little thriller with, as it happens, a terrific performance by the future superstar. Monroe's childlike distraction eerily suits her rattled character, a misfit who can't distinguish her tragic past from the confusing present. Kudos to Daniel Taradash (From Here to Eternity), whose script contains a collection of tart slang that neatly captures the noir feel--all without leaving the boundaries of the hotel.--Robert Horton,