Andrzej Wajda’s masterful Kanal (1957) chronicles one day during the last gasp of the Warsaw Uprising in September 1944, following a Polish resistance group’s doomed attempt to reach the centre of the city through the only viable route: its sewers. The second part of the War Trilogy that begins with A Generation (1954) and ends with Ashes and Diamonds (1958) it is, I think, the strongest, most sustained film of the three, and perhaps my very favourite of the Wajda films that I’ve seen. Kanal has the urgency and directness of documentary - indeed, archive footage plays under the opening credits - and yet in its depths of feeling, its sensitivity to atmosphere, the terror it evokes and its singular haunting beauty, the film goes way beyond what a documentary could give us. The scenes in the sewers in the second half achieve a primal, mythic intensity; the actors' faces, looming out of the shadows in this underworld, are unforgettable. Intense, harrowing and moving, this is one of the greatest war films ever made. Or maybe just one of the greatest films, period.