There's scant opportunity for director Nichols to impose any of his own personality on the film; he simply has to remain focused tightly on the characters as they wriggle from one uncomfortable revelation to the next.
The actors are extremely impressive.
Roberts brings a palpable fragility to Anna; her centre-piece scene, in which she nervously attempts to break up with Larry, is riveting for her obvious discomfort and guilt.
Law's pretty boy novelist is the least endearing of the quartet - vain, insensitive, spiteful, manipulative - but his unsympathetic portrayal makes Dan's inevitable comeuppance all the more delicious.
Portman continues her fine body of work with a scintillating performance as a woman attuned to the power of her sexuality.
Best of all is Owen, who played Dan in the original 1997 stage production.
As the Neanderthal, sex-driven doc, he blazes brilliantly across every frame of the screen, evidently relishing every loaded syllable of Marber's screenplay.
He's a shoo-in for an Oscar nomination. Everyone loves a cuckold who fights back.
