How should we approach the mystery of Adolf Hitler? As an inhuman monster, an alien in a sense, whose acts were so incomprehensible to normal human beings that we can never quite wrap our minds around a way into understanding him? As an insane man with the talent for inspiring and directing millions of people to kill millions of other people for no reason other than that he told them to do it? As the man whose talent was to give voice to the fantasies and frustrations of Germans in the 1920s and 1930s, releasing their own murderous tendencies and rendering their own consciences moot?

The film "Downfall" brings us a Hitler at the end, in April 1945, living in a bunker under the Chancellery in Berlin as the Russian armies close in. But it starts three years earlier, in 1942, when he hires a secretary, Traudl Junge, and shows himself a thoughtful, caring boss. (Junge, at the end of her life sixty years later, gave us a memoir about all this, as well as two interviews for the documentary "Blind Spot" that show how easily one loses perspective when given the chance to serve an admired boss.)

The film takes us through the last two weeks of Hitler's life, as his dreams, his country and his staff all break down around him. Bruno Ganz, the angel of "Wings of Desire," is Hitler, and he is amazing. He has found a way to make the monster believable, understandable, human. Not in the conventional sense as we understand humanity, but as a human being, one of us - not bright, not brilliant, not thoughtful, not intellectual, not a realist in any sense - and yet the iconic figure of the twentieth century and impossible to deny. Like the Germans at that time we are compelled to watch him; we cannot tear our eyes away.

Hitler's armies are collapsing, his generals are defecting, the perimeter around the chancellery is shrinking, and we see it all because we are in the bunker with him, and Eva Braun, and his dog Blondi, and Himmler and Goebbels (and Goebbels' wife Magda and their children) and Albert Speer - and of course Traudl Junge, who conscientiously transcribes all his orders. At the same time we catch glimpses of life up above: Eva leads the women outside for an occasional cigarette. Children are impressed into service as new soldiers. The Russian guns are blasting everything to rubble. The wounded are dying in a makeshift hospital.

But the bulk of the film lives in the harshly-lit, green-painted bunker rooms and corridors. At the beginning there is much action, as many of the figures, from generals to secretaries, bustle around doing their work. There are maps to be read, orders to be given, jobs to be done. But as the film moves on, there are fewer and fewer people around. Less and less is done because nothing can now stop the inevitable. But as the end nears, Hitler loses the remaining controls on his behavior and starts calling up fantasy armies, firing already-dead generals, describing the Germans as unworthy of his dreams, and then preparing for his own death - first, of course, marrying Eva Braun. And the Goebbels family chooses to die with him; the scene in which Magda Goebbels (Corinna Harfouch) poisons her children so that they will not survive into a world without Hitler is an agonizing reminder of the power of an insane vision.