Every once in a while a film sets up a thespian cage match so tingly that the poster need offer only the juxtaposed faces of the combatants to sell itself; Notes on a Scandal, Richard Eyre's (Iris, Stage Beauty) utterly compelling adaptation of Zoe Heller's bestselling novel (What Was She Thinking: Notes on a Scandal) is such a film. Starring Dame Judi Dench and Cate Blanchett -- looming large in Rushmore-esque profiles on the film's poster -- Notes on a Scandal delivers the giddy rush of a first class face-off in the ring, with all the strutting, taunting and roundhousing done on the inside, naturally. Fans of Dench or Blanchett or both will have an absolute shit fit watching the actresses grab their roles, and each other, with both hands (and in Dench's case, possibly a foot); the even better news is that the material they have to work with is more than up to the challenge, and the film itself a measured and yet gloriously overblown study of desire, entitlement and the twists we experience while shuttling between the two.

Dench plays Barbara Covett, a lifer at the London high school where she teaches, as a woman whose proud, viper-tongued persona belies the loneliness curdling her to the core. Charging through the halls in Aerosoles and a ratty blazer, her badly set hair showing almost tragic traces of some sort of tangerine rinse, Barbara moves (and teaches) like a surefooted grandmother. We soon learn, however, that her notebooks are where she truly lives her life; "chronically untouched," Barbara is so hungry for a confidant, a chum, a compatriot that she can't help but wolf down the humblest scrap of attention tossed her way. Even in her private musings on the subject -- conveyed in Dench's wickedly funny, and then just wicked voiceover -- Barbara parses out her hot-blooded longings in glassy-eyed, girlish terms, as though her development was stunted by a supernally confusing slumber party when she was 15.

When Sheba Hart (Blanchett) begins her first teaching job at the distinctly lower tier school, the scent of new blood in the tired pond causes a tizzy among the staff; Barbara in particular takes notice, from various corners, as the "wispy novice," attractive but innocuous, beaming shy modesty from behind her honeycomb fringe, is welcomed into the fold. Barbara finds her in after breaking up a fight in Sheba's classroom, and the two become fast friends as Sheba invites her to her happy home where her children -- one of whom has Down syndrome -- and husband (played by a superb Bill Nighy) can be found. Barbara goes home to her cat and her notebook to fantasize about trips to the shore and riding around on a bicycle built for two.

Blanchett is then given the unenviable task of nailing one of her students, a black Irish twinkler who looks every millimeter (and not one more) of his 15 years, played with a striking balance of innocence and experience by Andrew Simpson. When Barbara catches the two in the act, the jig steps up for both actresses in a remarkable scene where Sheba explains her actions by describing her sense of entitlement to the boy, to some pleasure -- a physical freebie earned with years of toil alone with her own troubled son. Watching (i.e. devouring) Sheba's anguish, Barbara's entitlement is piqued in turn: Why shouldn't she have some love, some satisfaction, after all these years; indeed, why should she not be rewarded retroactively, in spades, for such suffering? With a secret to bond them 4ever, Barbara sets out in earnest to extract Sheba from her family and solder them into a lifelong, pacific concord.

Blanchett is extraordinary as a woman sure she has been cheated (though not sure of what) and whose struggle with that void temporarily robs her of her senses. But Dench is perfection, and anything in her one-track, completely cracked path is just that: a bystander. The problem with Barbara is that she may be crazy, but (especially in her critiques of Sheba) often she’s also right: Who among us could stand to have our heart’s desire recited aloud, or dangled in front of us without lunging? Deprivation, among other things, has warped her into a small, surging ball of need, though her fangs are intact. Philip Glass's score races and throbs along with Barbara, and the film clips with alacrity toward its big, fat finish. With the exception of the coda, which smacks a little too much of hand-from-the-grave theatrics, as a clash of the titans Notes on a Scandal is the real thing, the extra inch, the whole 10 rounds. Can you stand it?