ALFONSO Cuaron's last film was Harry Potter and the Prisoner of Azkaban. This one is still set in the realms of fantasy - but only just.

It takes place in a near future where women are unable to conceive and the world is at war with itself.

Clive Owen is a careworn bureaucrat whose rebel heart has been stilled by the death of his son.

But he rediscovers his spirit when he is kidnapped by his ex-wife Julieanne Moore and her freedom fighters and asked to help take the world's last pregnant woman to a mythical place of sanctuary.

Cuaron orchestrates a series of jaw-dropping action set pieces that are staggering in their technical daring and breathtaking in their simplicity, seamlessly moulding inventive camerawork with unobtrusive special effects.

It's a tour de force of edgy Steadicam shots that plunge the characters, and us, into the centre of a war zone, recalling the same visceral thrills on the frontline as Saving Private Ryan.

Buildings explode under heavy artillery bombardment, background characters are scythed down in a hail of bullets and all hope is lost amid the bloodshed.

Owen delivers one of his best performances as a lifeless man, whose activist spirit is unexpectedly reignited by his contact with Kee.

He is in almost every shot of the film and effortlessly holds the attention.

Moore impresses in her pivotal supporting role, as does Michael Caine as an ageing hippie who still believes in a world full of love.

Children of Men (15): Thriller, directed by Alfonso Cuaron. Running time: 109 minutes.

Gazette rating: ***