The kids are definitely not all right in Gus Van Sant's coolly devastating account of a high school shooting. He bravely makes no attempt to explain the unexplainable, to provide insights into Columbine or any other massacre, instead simply portraying an ordinary day using ordinary students. Non-professional, improvising actors bring a raw, realistic edge that complemented its minimal, abstract style (it was shot for cable network HBO). The slaughter, when it comes, is made all the more horrifying for remaining unsensationalised and stunningly composed.

Mark Cosgrove, Watershed's Head of Programme, will introduce the film and discuss its significance.

Join the debate: you can message Mark directly using Twitter @msc45 or @wshed, using #decalogue.

Visit the Decalogue Website to get involved and get a decade's worth of debate started - leave a comment, share your 2000-09 movie memory, enter competitions and read about our reasons behind choosing some of the films.

Fee: £4.50 full / £3.50 concessions.