An extraordinary documentary has come along that, without raising its voice, has given us all a glimpse into, first, a mostly unknown Nazi horror, and then the selfless, courageous work of those who have tried to restore the heritage of a millenium. The film is called "The Rape of Europa," and it deals with a little-known side of World War II: the theft of artworks from the countries conquered by the Nazis.

As the Nazis invaded each country they made it a part of their offensive to appropriate for themselves as much art from each country as they could and bring it to their own museums in Germany. It was a priority for Hitler, who even in the Berlin bunker before he killed himself was still planning the architecture of his museum. And Hermann Goering, his second-in-command, took for himself as much as he could.

How many works of art did they take? No one knows for sure, but it was probably at least fifty thousand. Many, parhaps most, have been returned to the countries they were stolen from; some may never be recovered. "The Rape of Europa" documents both the thefts and the recoveries. Using footage from (mostly) Nazi newsreels, coupled with live interviews with those who've tracked down the artworks, both after the war and up to the present, the film lays out for us the extent of the thefts, and the enormous effort it's taken to restore at least some of them.

Narrated by Joan Allen and written by Richard Berge, Bonni Cohen and Nicole Newnham, who also produced and directed, "The Rape of Europa" takes us from a massive church altar in Poland that was moved whole, to the total wiping out of every Jewish art gallery, collector and synagogue in Paris. In some cases - the Louvre, for one - the staff was able to dismantle and cart away to safety in the rural south of France everything from the Mona Lisa to the Winged Victory of Samothrace.

The film also deals with the questions of proving provenance, particularly when the righful owners were gassed in the concentration camp ovens; the most recent example was Gustav Klimt's portraits of Adele Bloch-Bauer, now in a museum in New York.

The film is in no sense a dry lesson in art history; it manages to pack in some extraordinary footage of both the thefts and the recoveries; it has the impact of a great detective film, with of course the added power of being true. The film is not to be missed by anyone with an interest in art.