Handing action maestro The Rock a proper script would appear akin to pencilling in Vinnie Jones for a lead role in The Hours.

However, the former wrestler and star of The Scorpion King rises to the occasion and even displays a neat sense of comic timing you wouldn't expect.

As tough mercenary Beck he uses whatever means necessary to bring back what he's been paid - from a gold ring from a debt-laden quarter back...to an errant son.

What he really wants to do is run a small restaurant where he can refine the recipes he copies down in a notebook from a radio cookery show.

But before settling down he has to do one last job - head off to the Brazilian jungle and bring back maverick youngster Travis (William Scott).

So, if you like, we have a wannabe Ainsley Harriott except one trained by the SAS, making off to South America to retrieve a reluctant fast-talking double-dealer.

Of course, it's not quite that simple. Firstly, Travis doesn't want to come back because he thinks he's discovered a priceless artefact deep in the forest.

Secondly, the whole region is run by Christopher Walken's unhinged Hatcher, a gold prospecting nutter keen on exploiting the locals.

Director Peter Berg wouldn't be the first choice as an action director (he first made his name as an actor) and that's what distinguishes this amiable ninety minutes of hokum.

There's greater attention paid to characterisation with The Rock a revelation as the wryly tough but fair enforcer and William Scott basic relocating Stiffler of American Pie infamy to the jungle.

Walken appears to have a proviso in his contract which means he can insert his own doolally dialogue and bolster the skewed portrayals he's made his own. Which, of course, he does.

The stunt setpieces are well up to muster with a particularly impressive tumble by Beck and Travis down an almost sheer mountainside and the script's above par for these sort of things.

"I never met an American who doesn't like guns," one thuggish henchman comments on the intentionally unarmed Beck.

Tim Evans