Never-before-seen footage of Marilyn Monroe behind the scenes of her last completed film will be auctioned in Las Vegas this weekend, the BBC reports. The silent 1961 reels show a relaxed-looking Monroe talking to the cast and crew and having her hair done as she works on The Misfits with Clark Gable. The late actor also appears in the footage, which is expected to sell for some $20,000. (More film stories.)