'Smokin' Aces' is a high octane ensemble piece which gets most things right in its efforts to create a fast paced thriller, meant to keep you guessing until the final scene.

The story begins with mobster and magician Buddy 'Aces' Israel (Piven) trying to cut a witness protection deal with the FBI. This, of course, is something his former associates aren't too happy about, so they set about hiring a gang of contract killers with instructions to take him out.

This motley crew consists of cool and sassy black chick, scar-faced silent guy, Hispanic moustache guy and 'Mad Max' extra guys. They're all excellently played, with film acting debutante Alicia Keys particularly impressive in her role as a sultry assassin. Oh, and Ben Affleck's there as well and... well, something sort of important happens to him.

Meanwhile, a team of FBI agents spend the whole movie one or two steps behind the bad guys. The agents are great, spending most of the film asking each other questions, giving each other back story and providing handy summaries of the action to help slightly dimmer members of the audience keep up (well, I appreciated them anyway).

Even without the help of the bungling Feds, most people will be able to tell the substance if not quite the detail of what's coming from fairly early on. It's as though writer-director Joe Carnahan raided a scriptwriters' conference on obvious and see through storylines and made off with some plot devices.

After this setup comes a quite excellent middle sequence. Carnahan creates a terrific sense of convergence, effortlessly achieving perfect pace and a sense of unstoppable momentum that is a pleasure to watch. The audience can't help but get carried along to the point where the killers all arrive at Buddy's penthouse at the same time.

Then, the assassins put their plans in motion and we are treated to a sustained and shocking series of shootout scenes. These really and truly are among the bloodiest I have ever seen, so much so that I felt a little sick, which isn't like me. If blood and guts upset you unduly, 'Smokin' Aces' is one to miss. This is a pity, because the gore adds nothing whatsoever to the film.

Unfortunately, the pointless grisliness is not the only problem. Things elsewhere also start to fall apart slightly during the film's denouement.

First, the tone falters with a late shift towards pretentious posturing that's as unexpected as it is unsuccessful. This failure really comes down to the inability of Ryan Reynolds' 'good guy' FBI agent Messner to engage or move us in the slightest.

'Smokin' Aces' is for the most part an excellent black comedy and Messner's 'Hamlet'-style posturing at the end is a bum note rather than a counterpoint to the madness.

Meanwhile, the attempt at a 'Usual Suspects' moment is predictable and unsatisfying; a plot twist that is more forehead slapping than mind bending.

Generally speaking, though, the excellent performances by the whole ensemble, the crackling dialogue and the terrific pacing just about make up for a slightly silly plot and a misguided attempt to say something important at the end.

Brendan Cole