“Density,” reckons Ridley Scott, is what drew him to this adaptation of US Middle-east journalist David Ignatius’ novel. Boy, can’t you tell? Deception and optical dazzle are the defining currents of this thriller. And you can’t see much through the dense clouds tossed up.

Not that Body Of Lies is lacking thrill value. As a CIA agent sent over to Jordan to sniff out a terrorist, Leonardo DiCaprio looks chunky, sports Clooney-ish man fuzz and steps that bit closer to looking all grownup. Russell Crowe is playful as his senior, dispatching telephonic orders. The real star though is Mark Strong: keen and deadly as Jordan’s secret service head.

The movie’s message spins out from the tension between Crowe’s backstage callousness and Leo’s frontline-forged conscience: as Ignatius argues in a sharp interview, it’s about how America doesn’t “know enough to do some of the things we do”. Thumping ‘obvious theme’ alert? Sure, but the plea for greater understanding rings true and welcome.

Shame, then, that William Monahan’s script and Scott’s direction muddy that understanding. The tangled plot plays less like “density” than a mess. Explosions substitute for real tension and when SUVs whip up dust to muddy a surveillance system, a metaphor for the film is implied. Granted, the brash and confidently acted result is never less than watchable. Memorable, though? Enlightening? They’d be porkies.

Kevin Harley