At Auschwitz, while trainloads of Jews were being sent directly from the arrival dock to the gas chamber, the Nazis one time held back two "transports" from Czechoslovakia. The Czech Jews were put in isolated barracks. Families were kept intact. Children were allowed to mount plays, and the adults were encouraged to write letters to relatives describing their experience in this new place. Then they were all gassed.

They were driven to the gas chamber. They were ordered to strip. They were punched, kicked and clubbed, and some were killed on the spot. But somehow, someone -- and then everyone -- started to sing the Czech national anthem and then "Hatikva," a Zionist song that later became the Israeli national anthem. Its English title is "The Hope."

It was then that Filip Muller, a Jew whose job it was to clear bodies from the gas chamber, thought he could take no more -- no more killing, no more waiting for his own end in the periodic purges of gas chamber and crematorium workers. He walked into the gas chamber and then, at the pleading of a woman, walked right out again. She gave him a reason to live.

You will meet Muller if you see the movie "Shoah," which is 9 1/2 hours long and which is the ultimate film document of the Holocaust. You will hear Muller tell his story and then you will watch him break down and cry. I guarantee you will cry too. You will cry because Muller's story is awful, sad, beyond comprehension, but also because -- miracle of miracles -- after all Muller saw and did, he still can cry. In fact, he can't stop himself.

And neither can Abraham Bomba, barber, of Tel Aviv, but once barber at Treblinka, the Nazi extermination camp not far from Warsaw. His job was to shear the heads of women before they were gassed. Snip. Snip. It had to be fast because there were schedules to keep. Standing in a Tel Aviv barbershop and cutting someone's hair, he tells of the day when his fellow barber at Treblinka had to cut the hair of his own, doomed wife. Wordlessly, she sat for her shearing and her husband could do nothing for her. He could only dawdle, take a second or two longer. At this, Bomba is forced to put down his scissors and interrupt his tale. He, too, can cry.

There are others. The almost legendary Itzhak (Antek) Zuckerman, one of the few Jews to survive the fight for the Warsaw ghetto. Now, in Israel, he says, "If you could lick my heart, it would poison you." Or Rudolf Vrba, sort of a trusty at Auschwitz, who escaped after the gassing of the Czech Jews to tell an uninterested world that the Nazis were exterminating the Jews of Europe. Or Jan Karski, the non-Jewish Pole who lives now in Washington. He smuggled himself into the Warsaw ghetto to see firsthand what was happening -- the people falling dead on the streets, the hordes of orphans, the mounds of bodies: a culture dying of induced starvation. And he, Karski, bursts into tears.

This is the film of Claude Lanzmann, the French film-maker. When one of the people he is interviewing breaks down and says he cannot continue, Lanzmann says he must. He says that he is preparing a historical record. He says that the testimony is ugly, painful to say, painful to hear but the pain, ultimately, is beside the point. History asks a bit more from these people: say for the camera what it was like. The interview subject gulps some air. And goes on.

As a history of the Holocaust, there are no facts in "Shoah" that are new. Its virtue is the medium of film -- the faces you see, the voices you hear. And oddly, the fact that it was shot in color makes a difference. This is not a dusty, archival look at history -- at the dead and the artifacts of death like what's left of the crematoriums. The witnesses are here among us -- barbers and intellectuals and, of course, the many Poles who watched the trains to Auschwitz or Treblinka, who even drove them, who could do nothing to stop the murder, who sometimes did not want to stop the murder, who to this day cannot comprehend it and who sometimes find their answer in the foul libel of the Jew as the killer of Christ. To them it is not so much an excuse as it is an explanation.

In the gas chamber, Filip Muller met a woman who knew him -- knew he was a worker who could live, if he chose, if only for a while longer. She told him to go back. His death would change nothing. He had to live. He had to bear witness. It was, she said, his obligation.

See "Shoah." It is your obligation.