The images in Fritz Lang's films exist on a permanent borderline. Are they something we dreamed or something we glimpsed, unwillingly, out the window? Did we desire them, or did we want above all else to keep them at bay? The stairs of a high-rise clogged with evacuated workers, a factory complex exploding in the middle of the night, a nightclub audience mesmerized by the dance of a sexy automaton, a city subjected to a block-by-block search for a child murderer: This is the language of crisis, yet it's a crisis without any obvious exit or solution, a crisis whose patterns are teased out by an aesthete of catastrophe. What most disturbs about Lang's movies is our continuing perplexity about what they are for. From the global criminal conspiracy of Spiders (1919–20) to the two-way mirrors of The Thousand Eyes of Dr. Mabuse (1960), from the archaic conflagrations of Kriemhild's Revenge (1924) to the apocalyptic gangsterism of The Big Heat (1953), Lang leads us over and over again into the heart of a permanent emergency—whether it's the outbreak of war or the strangling of a showgirl—without telling us why. All we know is that we aren't allowed to look away.

We can't look away, that is, if we are able to look in the first place. Seeing Lang's movies in decent prints and at full length hasn't always been easy; the German classics have been seen in the US almost exclusively in drastically cut versions, and American films like House by the River (1950) and Human Desire (1954) are hard to find in any form at all. While waiting for a stateside retrospective on the order of the one held recently at the Filmmuseum Berlin, we can at least savor the immense catalogue published in conjunction with it. It is a curious dossier, despite its title neither biography nor critical survey, but rather an assemblage of evidence, with text in German, French, and a sometimes mangled English. It's as if Lang were, if not a criminal, at least someone under grave suspicion, whose activities needed to be examined piece by piece with an eye for the detail that doesn't fit. One pictures Inspector Lohmann, the avuncular police chief of M (1931) and The Testament of Dr. Mabuse (1933), spreading these letters and notebooks and photographs over his desk and muttering to himself: "Na ja, it is a complex case, we must look for the pattern."

Readers of Patrick McGilligan's Fritz Lang: The Nature of the Beast (1997)—still the only full-scale biography—will recall a portrait that, despite a swirl of contradictions, resolved itself into a figure of monstrous vanity and ambition, servile to superiors and tyrannical to underlings, someone who might well be suspected of unspeakable crimes and vices—always with the proviso that nothing can be firmly stated due to insufficient evidence. McGilligan's loss of empathy toward his subject was so marked that after a while the reader had to wonder whether the director was being given an altogether fair shake.

The present compendium (the volume's physical heft makes the word singularly appropriate) seems in part designed to put forward, in deliberately neutral fashion, some counterarguments in Lang's favor. Where McGilligan drew, out of necessity, on a good deal of speculation and gossip, this catalogue sticks to what can be documented, the more official the better. Thus we have birth certificates, enrollment certificates, passports; Lang's receipt book as a much decorated combatant in World War I; a certificate of good conduct issued at the request of French authorities by the police chief of Berlin in 1934, after Lang's emigration to Paris; FBI files noting Lang's connection with such doubtful characters as Bertolt Brecht and Hanns Eisler (including a 1951 notation that Lang was "a talented director but politically a child, a 'sucker' for organization sponsor and donor lists").