Cate Blanchett, with her dewy libidinous-lipped sensuality, and Judi Dench, with her glaring royal-witch disdain, make a lusciously entwined pair of comrades-turned-combatants in Notes on a Scandal. Directed by the up-until-now mediocre Richard Eyre (Iris, Stage Beauty), and based on Zoë Heller's 2003 novel, this is one of those sensationally nasty and clever psychological thrillers that reach back to what Patricia Highsmith invented more than half a century ago in Strangers on a Train (1950). Once again, a ripe innocent is befriended by a lonely and deceptive predator with lurkingly creepy motives. Sheba Hart (Blanchett), freshly arrived at St. George's School in north London, is an upper-crust art teacher with two children and an older, rumpled academic of a husband (Bill Nighy). Barbara Covett (Dench) is a veteran instructor at St. George's, a spinster with a fixed frown and bile in her veins, who becomes obsessed with Sheba: her winsome looks, her boho bourgeois ways, her hidden desires.
The fun of Notes on a Scandal is torn from the tabloid headlines, as Sheba, out of boredom and repressed anger at her family, begins to sleep with a 15-year-old boy at her school, and Barbara, who spies the two going at it, seizes the chance to blackmail the younger woman. Yet the movie's truest note of scandal is the way that it dares to tap a closeted 1950s craziness of deepest sexual incorrectness, making Barbara into a figure of exotic treachery for her furtive lesbian desires.
Notes on a Scandal seduces the audience in a fresh, off-balance way, inviting us to enter the film not from the point of view of the ''normal,'' preyed-upon heroine but from that of the poker-faced stalker in this case, Dame Judi, teasing us in voice-over as Barbara dissects everyone around her like a closet sadist pinning down live butterflies. She even holds contempt for Sheba, the object of her desire, whose existence she parses with the pitiless accuracy of a particularly misanthropic shrink. Where does Barbara's contempt come from? As portrayed, it is old-school British class jealousy mingled with a lifelong loner's horror of domesticity, all wrapped up in the pathological dream that Sheba would leave her home to be with her.
Dench acts with her familiar rigid features (the puffed lower lip, the glower of contempt), as well as those caustic, steel-cut theatrical rhythms. Only here, wearing less makeup than usual, her hair disheveled, she makes Barbara into a figure of cruel depression, a monster-frump lashing out with toxic wit at a lifetime of unhappiness. It's a scary, funny, and towering performance. Blanchett, meanwhile, breathes life and sympathy into an ordinary woman with a secretly messy interior, even if the blitheness with which Sheba allows herself to stray into let's call it what it is child abuse is never fully explored. Notes on a Scandal had more texture as a novel, though it also had less Highsmithian genre snap. As a movie, it's a poison bonbon tastier than just about anything else out there.