LET me say up front, with no hint of shame, that I have no idea what I Huckabees is about.

Even on second viewing, David O Russell's existential comedy is still infuriatingly, wilfully obtuse and impenetrable.

The film is the cinematic equivalent of a Moebius strip - the characters go round and round and seem to end up almost where they began. We're left woozy by the experience.

These disparate souls spout snappy dialogue at each other, which is sporadically amusing (a running joke about Shania Twain), sometimes heartfelt and frequently cryptic or nonsensical ("I'm in my tree, I'm talking to the Dixie Chicks and they're making me feel better.").

And yet, indescribable and perplexing as I Huckabees most certainly is, I quite enjoyed this journey into the minds of the disaffected and disgruntled.

I don't know why I enjoyed it - perhaps for Russell's audacity in unleashing this conundrum on the multiplex-going masses, or for the ensemble cast who seem to know what's going on even if we don't.

The unlikely hero of this bewildering piece is tireless environmental campaigner Albert Markovski (Schwartzman). He heads the Open Space Coalition, which is devoted to saving the Earth's dwindling resources.

Albert feels his life is going nowhere, so he hires a husband and wife team of existential detectives - Bernard and Vivian Jaffe (Hoffman and Tomlin) - to delve into his psyche.

The Jaffes assign eco-friendly fireman Tommy Corn (Wahlberg) to be Albert's spiritual buddy, shepherding him through the difficult times ahead.

Tommy is a kindred spirit for Albert, refusing to pollute the environment by travelling in the fire truck. Instead, he races to each scene on his trusty bicycle. ("We'd all be heroes," he notes sagely, "if we stopped using petroleum.")

The nosey duo pick out scheming executive Brad Stand (Law), whose company Huckabees supports the Open Space Coalition, as a major cause of Albert's current frustrations.

So Bernard and Vivian take on Brad as a client, too. When they delve into his personal life, they expose a rocky relationship with his model girlfriend Dawn (Watts).

But their investigation is hampered by the unexpected intervention of a rival detective, Frenchwoman Caterine Vauban (Huppert), who rejects Bernard and Vivian's methodology and proposes her own radical approach to self-fulfillment.

"It is inevitable to be drawn back into human drama," she philosophises at one point.

Someone pass the headache tablets.

DAMON SMITH