Security guards open a door to reveal "Salvator Mundi" by Leonardo da Vinci during a news conference at Christie's in New York, Tuesday, Oct. 10, 2017. The piece, which was painted around 1500, is one of fewer than twenty da Vinci paintings known to exist. After public exhibitions around the world, the auction is scheduled to take place on Nov. 15, 2017. (AP Photo/Seth Wenig)