A landmark historical film discovered by FRONTLINE in a museum vault decades ago has been called "Hitchcock's lost Holocaust film." First broadcast by the series in 1985, the documentary shows the first horrifying footage shot as Allied troops entered the Nazi death camps. Drawing on initial editing done by famed director Alfred Hitchcock before the film was shelved 70 years ago, FRONTLINE reconstituted the forgotten reels and script and showed them in public for the first time 30 years ago.