In Darkness (15)

Starring: Robert Wieckiewicz, Benno Fürmann, Agnieszka Grochowska

The Righteous Gentile of the Holocaust movie – the one who puts aside self-interest and safety to rescue doomed Jews – reached its pinnacle in Schindler's List.

The Oscar-nominated In Darkness focuses, dimly at first, on a much less noble exemplar. In Nazi-occupied Lvov, Poland, Leopold Socha is a lowly sewer inspector who moonlights with his young assistant as a house-breaker, hiding his loot in the underground tunnels he knows better than anyone. He has a wife and daughter he loves, but he's really a scoundrel, an opportunist – more swindler than Schindler.

Played magnificently by the potato-faced actor Robert Wieckiewicz, Socha is one of the least likely humanitarians you can imagine, though he knows what's happening around him. Flitting home through the woods one night, he sees a line of naked, terrified women being hustled at a run by German soldiers; minutes later he hears a long rattle of machine-gun fire. He also bumps into an old prison associate Bortnik (Michal Zurawski), now part of the Nazi-sponsored Ukrainian militia, who tells him of the big pay-outs for handing over Jews. So when he encounters a group of Jewish fugitives hiding out in "his" sewer he is at once disgusted and excited: he calls them "a bunch of lice", but he delays turning them in because they have money to bargain for their lives. As he confides to his assistant, he can make them pay now and shop them later.

The film, adapted by David F Shamoon from Robert Marshall's book In the Sewers of Lvov, seems to be operating on two levels. As the "darkness" of its title suggests, we are witnessing a hell on earth, that horrific and barely conceivable era in which nations preyed on their own citizens like wolves. It's also a hell below earth, a literal darkness of cramped and fetid sewers where a few survivors of the ghetto liquidation above huddle together in the shadows.

This is part of the technical challenge faced by director Agnieszka Holland (veteran of an earlier Holocaust movie Europa Europa) and her cinematographer Jolanta Dylewska. They brilliantly capture the claustrophobia and the rat-infested filth of the tunnels, while the vanishing outlines of humans contain an almost painterly aura of light and shade. At the beginning of their ordeal the half-lit figures look like something from medieval religious painting. By the end they look like the gaunt ghosts of Egon Schiele.

The problem with this darkness is the practical one of individualising characters – we can barely make them out. For example, two people are conducting an adulterous affair in the hide-out, but at least an hour passed before I could be certain which woman was being cheated on. It takes someone very striking to be identified through the murk: one such is Mundek (Benno Fürmann), a pragmatic German Jew who becomes the group leader. His distrust of their paid-for saviour Socha shades towards hatred – "you can't trust a Polack" – and makes clear that the Jews are by no means innocent of the contemporary race prejudice. (The film's mixture of tongues includes Polish, Yiddish, German and Ukrainian).

The palette of black and blacker is naturally oppressive. Holland, aware that an audience needs a respite, makes timely visits to the daylight world, though of course the danger here becomes that much more acute. In one heart-stopping sequence, Mundek somehow finagles an entry into Janowska concentration camp so as to make contact with the sister of Klara (Agnieszka Grochowska), the woman he loves. The daring of this seems so outlandish that one feels it must be based on truth. The random atrocities Mundek witnesses also have a straight-from-life horror, though for most of us they come through the inevitable filter of other Holocaust movies, primarily Schindler's List, but also The Pianist and the superb The Counterfeiters.

What sets this one apart is the Righteous Gentile himself, Socha, whose struggle highlights a possible third layer of meaning in the film's title: it is the impenetrable darkness of the human soul, the mystery of why a man of no great moral purpose will decide to risk his life saving a handful of despised strangers. Is it the spectacle of their degradation that moves him? The presence of two children among the fugitives? Or an inkling that mere ignorance has condemned the Jews as outcasts? (He himself is surprised to learn that Jesus was a Jew). To make such a turnaround convincing would test the powers of a great novelist. For a film-maker the means at hand are so much less subtle, so Holland made one of her best decisions in casting Wieckiewicz as the lead. His shifty eyes and unprepossessing face never promise any great spark of humanity, yet the cumulative force of what he experiences seems to alter him out of recognition.

Towards the end the film allows itself a couple of scenes that a disciplined scriptwriter would have scorned as too "movie-ish". The first is a love scene played out beneath a cleansing flood of rainwater: a primitive version of sex-in-the-shower. The second is a tense moment when Socha's daughter seemingly betrays his charges in front of the Jew-hunting Bortnik. Again, it's not that it's badly done – it really is tense – only that you've seen it done many times before: file under "the perilous nature of innocence". It is a pardonable lapse. The challenge of making a Holocaust movie involves, over and above a memorialising of the dead, a moral quandary. Its task is singling out the exception, the one-off, and deciphering why this particular person found compassion when so many others did not. In Darkness can't decipher it. All it says is this: the least likely of us are capable of it.