REVIEWED - DÉJÀ VU:Denzel Washington finds himself with plenty of time on his hands in Tony Scott's loopy sci-fi thriller, writes Donald Clarke

IF YOU were able to travel back in time and change history, what would you do? Perhaps you'd set the imagined temporal transporter's destination settings to South Shields in the early 1950s, seek out Tony Scott upon arrival and, happy dreams of a future without The Hunger or Days of Thunder racing through your brain, push the still blameless little tyke off a bridge.

Then again, maybe you wouldn't. After all, what sane person would pick on young Master Scott and leave Michael Bay free to contemplate his even more unlovely monstrosities?

Besides which, Déjà Vu, Scott's latest emission, is really not that dreadful. It's not good, you understand. This characteristically sleek entertainment is relentlessly implausible, morally dubious and, like virtually all time travel movies, riddled with puzzling narrative wormholes. But, for the first hour at least, it zooms along at a cracking pace and, profiting from Scott's vulgar visual invention, remains busy enough to distract the viewer from asking too many questions.

The film, which is shot in New Orleans and features several clumsy allusions to Hurricane Katrina, begins with the detonation of a bomb on a packed river ferry. Denzel Washington, an operative for that puzzling US entity, the Bureau of Alcohol, Tobacco and Firearms, is dispatched to gather evidence and, eagle-eyed as he is bizarrely fortunate, quickly comes across some bewildering anomalies.

Recognised as a man to watch by his superiors, he is assigned to a new division using advanced technologies to solve particularly serious cases. The team of boffins claim they are using satellite technology to assemble startlingly comprehensive and well-defined composite footage of the crime scene four days earlier. But Washington, either prescient or a raving lunatic, soon figures out that the scientists have found a way of looking into the past.

While the protagonists are merely using their discovery for retrospective surveillance, the film works quite nicely. One fine scene, as absurd as it is exciting, sees the hero dodging traffic as he follows the villain's movements four days earlier (perhaps you had to be there).

Sadly, Scott and his cronies eventually succumb to the temptation to send Washington back in time and the initial high-concept fades away to be replaced with dizzying silliness and repeated egregious flouting of Star Trek's Prime Directive. Déjà Vu? You've seen it all before.