The Polish film-maker Agnieszka Holland began her career in the 1970s working with Andrzej Wajda and Krzysztof Zanussi before making an impressive debut with Provincial Actors, in which she used a rep company and its discontents as an image of Polish life in the run-up to the creation of Solidarity. She's since divided her time between eastern Europe and the west, where her work has ranged from Washington Square to episodes of The Wire. Her latest Polish film, the tough, unsentimental In Darkness, brings together themes from two of the most highly regarded movies about the second world war, Wajda's Kanal, about Nazi troops pursuing resistance workers through the Warsaw sewers in 1944, and Schindler's List, Spielberg's true story of the quixotic German industrialist who saved the lives of more than 1,000 Jewish workers in wartime Poland.

Holland's film is also closely based on fact. Leopold Socha (Robert Wieckiewicz), a sewer worker in German-occupied Lvov, with a sideline in petty theft and exploiting persecuted Jews, takes money from a party of escapees from the Lvov ghetto hiding in the sewers. Like the rather grander Schindler, he ends up risking his life protecting them, a courageous action for which he was posthumously honoured by Israel as a "righteous gentile".

It's a harsh, unsanctimonious picture with none of the feel-good elements that Spielberg inevitably injected into his story. Socha's conversion is slow, reluctant and convincing. We are spared none of the horrors of Nazi brutality above ground or the terrible sufferings in the stinking, claustrophobic hell beneath, and there's a scene of childbirth down in the sewer which verges on the unbearable. It's a long movie, but it compels you to experience something of what it was like to live for 14 months hungry, cold and knowing that at any minute the agents of a cruel, vindictive regime could arrive to treat you like the rats that shared your sewer.