United 93 (15) <!-- none onestar twostar threestar fourstar fivestar -->

Fasten your seatbelts

Orson Welles once observed that there were only two kinds of emotion on a plane: boredom and terror. The British writer-director Paul Greengrass has distilled the latter into a very concentrated form in his momentous drama United 93 and, in doing so, pushes cinema as close to an ordeal as it can get. In the last five years it has become impossible for all but the superhumanly nerveless to step into an airline cabin without at least sensing the ghost of September 11. This movie not only reawakens that subliminal anxiety, but forces us to contemplate the unbearable: the last minutes and seconds of passengers who knew they were about to die.

Greengrass, who began his career in documentaries, was the right man for this job, as anyone who saw his dramatic treatment of the Irish civil-rights massacre Bloody Sunday (2002) will vouch. Someone once defined documentary as "the creative treatment of actuality", which could also describe what Greengrass has done here. The actuality of what happened on board United Airlines flight 93 on the morning of 11 September, 2001 will remain largely unknowable, but the concerted forces of imagination, craft and informed guesswork persuade you that this film offers a creative, if not quite a literal, truth. Using hand-held cameras and filming in something very like real time, Greengrass puts us in almost intolerable proximity to how it must have felt. What the film does expertly is to play the audience's foreknowledge off against the unsuspecting pre-September-11 world. For them it's a day like any other; for us it's the day.

It begins in the darkness of a motel room, where we hear a Muslim voice intoning prayers, then cuts to the diurnal business of passengers and crew members arriving at Newark Airport, where United 93 is being prepared for the morning's flight. Running concurrently with this are the shifts at the control centres of Boston, New York and Virginia, a busy medley of networks just easing into the rhythm of the day. It's a heart-breaker to watch people getting ready like this, and to know how absolutely unprepared they are for what's about to happen - the soothing banalities of the safety procedure and the innocent chat between flight attendants and passengers take on a tragic irrelevance. Greengrass understands this for the torture it is: when one passenger rushes to catch the flight and arrives at the cabin door with minutes to spare, you could weep for his terrible timing.

As luck would have it, the flight is delayed, and takes off just after the first, vague reports of a hijacking filter through. At the Federal Aviation Administration centre, they're thrown into confusion as one flight, then another, veers off course. Why is there no response from the cockpit? Have these airliners really been hijacked? Suddenly we start hearing lines that chill us, like the report of a plane, American 11, "still descending east-bound towards New York". The new operations manager, Ben Sliney, looks a relaxed, can-do sort of guy, but even he can't fathom this one, and if his bafflement looks realistic that's because he's played by Sliney himself. This is another aspect of the film that Greengrass gets right: he mixes a cast of real pilots, controllers and flight personnel with mostly unknown actors (I recognised only two faces), realising that a star would puncture the bubble of authenticity. He doesn't demonise the four young hijackers, either, in spite of their unspeakable crime, and even dares to suggest that one of them has second thoughts about his mission. I wonder if an American director would have dared so much.

Thinking about the movie later - you can't help it - the commitment of the cast inspires admiration all over again, for not only were they obliged to honour the memory of the recently dead and the feelings of their relatives, but they also had to do a convincing minute-by-minute impersonation of panic that turns into suspicion that turns into horrified certainty. That it does convince is due to Greengrass's careful preparation: the chaos following the hijackers' takeover, the passengers' retreat to the back of the cabin and the frantic debate about what they should do seem absolutely spontaneous, yet are likely the result of disciplined rehearsal.

The dawning realisation of their fate - mobile-phone calls to their loved ones have apprised them of the planes hitting the World Trade Center - eventually prompts a handful of the passengers to take action. In retrospect, the idea of rushing the terrorists to gain control of the cockpit seems the obvious thing to do, the only way of saving their own lives. But, confined within the nightmare of that plane, the "obvious" thing to do may also have been the most terrifying of all. Would it not have been easier to stay put and believe the passenger who says: "They'll ask for a ransom and let us go"?

Greengrass handles this climax with an assurance that is at once heart-stopping and curiously matter-of-fact. While we see some of the younger men brace themselves for the counter-attack, their heroism remains low-key; even the famous "let's roll" line is unemphasised, not a war-cry, just a quietly determined exhortation. We have watched this movie knowing all along that United 93 is doomed (the plane crashed in a field in Pennsylvania, killing all on board), yet the gruelling exhilaration of these final 15 minutes force on you the impossible, paradoxical hope that somehow these brave people will survive. That hope turns to anguish as we watch other passengers sending their goodbyes and messages of love down phone-lines: the end is coming.

United 93 powerfully suggests what ordinary people are capable of in circumstances of extraordinary horror. If only we could emerge from it and think: "never again".