Joel Schumacher's sideboard is one seldom troubled by Oscar. After all, even the Academy would balk at rewarding the very least Batman flick or that cack-handed, reactionary Grisham adaptation A Time To Kill. Or, indeed, 8MM. Although, to be fair, this last is by the far most interesting. It too may be reactionary drivel - it's just harder to tell.

From a script by Se7en-man Andrew Kevin Walker, it has Nicolas Cage as a private dick hired by the widow of a wealthy industrialist to investigate the roll of 8mm found in his private safe - film that appears to document the final minutes of a terrified young woman. Thus Cage and tattooed help-mate Joaquin Phoenix (rather good) are plunged into the violent underworld of the Los Angeles porn scene, rubbing 'til it bleeds.

It's hard to tell for sure, but one suspects Walker's original intentions have been re-routed. The film repeatedly pushes towards ambiguity only to find itself dragged bodily into the light. Schumacher seems determined to impose a clarity of purpose upon the material, a morality it scarcely deserves. It's a feeling underlined by casting Cage. Sure, he's buttoned-down, but too buttoned-down, too easily shocked in the beginning, too easily corrupted by the chase. The film has echoes of Paul Schrader's Hardcore, but lacks that film's righteous anger. It stretches for evil in its over-busy design but, we suspect, comes closer to the truth in those silly, lazy moments when it indulges cheap Goth high-heels and PVC rapist masks. It calls for, at the very least, what someone like Johnny Depp could have brought. Better yet, what a Steve Buscemi would have offered in spades.

Consequently, Cage is sidelined by fiery, sometimes ludicrous but always more interesting supporting players: Peter Stormare's sleaze-flick supremo Dino Velvet, the Jim Jarmusch of bondage; Sopranos mainstay James Gandolfini as a sweaty low-rent porn-vid maker; and the wonderful Catherine Keener, given nothing to do as Cage's mummsy wife, but constantly outstripping him even there.

And things go from bad to worse in the final third, where the film apparently winds down only to start up all over again, turning itself - or at least wishing it could - into Taxi Driver, albeit with none of the same impotent rage. It goes some way to explaining the sheer banality of evil, but only through Cage's transformation to comic book avenger. By that point Schumacher has lost his audience, simply ploughing on with what has long since become an overloud, preachy and effortlessly nasty spectacle. Only Mychael Danna's dazzling score earns top marks - just a pity it wasn't dedicated to an altogether better project.