Sheba beats into Barbara, with tongue and fist, how Barbara's secret attachment and manipulativeness, her snideness and self-regard, appear to an observer whose disenchantment now equals her own. It is immensely, theatrically gratifying to have Sheba fling some home truths directly into the Gorgon's face, with a glass-splinter wit to match Barbara's own but an electrified physicality pushing it home. And the inadequacy of Barbara's responses jacks the comedy up that much further while deepening the pathos. When Sheba yells that she could get two years' prison as a result of Barbara's snitching, Marber has the older woman attempt to soothe her with, "They'll fly by! I'll visit every week." It's a miraculous high point, one of the crispest displays of pyrotechnical temperament in movie history and thoroughly dictated by the narrative structure. It provides as great a release for viewers as sex would have been for Barbara.

Worked up beyond the power of articulation, Sheba runs out with the incriminating diary among the press lurking outside Barbara's door. She cannot bring herself to retaliate, however, but can only roar, nightshade queen of the mosh pit one last time. Suddenly bewildered and self-conscious, Sheba goes back inside with the notebook still in hand. She attempts to speak plainly to Barbara — elucidating, for instance, the insignificance of a merely polite invitation she had made some time back — and can only marvel that Barbara can't take in even this much. Finally, with exhausted and pitying generosity, Sheba returns the diary to its mad author and leaves, the surest sign that this is naturalism and not melodrama. Naturalism in an ironic-tragic vein, because Sheba isn't well suited to the changes that will be necessary from here on out and Barbara is incapable of them. Sheba at last understands what's been going on but what will her spiritual indolence be like without her illusions of safety? As for Barbara, we can guess what she'll be up to with the next compliant young thing she comes across.

Last but not least, this is a great stride forward for Richard Eyre, who manages to keep the highly internal intrigue from becoming self-consciously "literary" (practically a miracle after his work on Iris [2001] and the literal-minded yet prancingly self-pleased Stage Beauty [2004]). In terms of movement and complexity, Eyre's work here can be spoken of in the same breath as Fred Schepisi's adaptation of John Guare's Six Degrees of Separation (1993). Working with the super-alert present-tense cinematographer Chris Menges and the film editors John Bloom and Antonia Van Drimmelen, Eyre moves the story along swiftly and yet never descends into moviemaking "flash." You may not be aware of his hand, but that's because he gets both the emotions and the irony breathlessly right. The story fairly absorbs you. And what he's done for these actresses deserves some kind of monument.