15, 95mins

Patrick Marber’s adaptation of Zoë Heller’s 2003 novel, Notes on a Scandal, is screenwriting at its vicious best. There is a queasy sense of doom when we clap eyes on Judi Dench’s grim and cynical history teacher as she sizes up the exotic new art teacher (Cate Blanchett) at the beginning of term. “Is she a sphinx or simply stupid?” muses Dench.

These are the secrets she stores up and religiously commits to her diary. We love Dench’s wonderfully liberating contempt for the thick pubescent pupils and the worthy stiffs in the common room.

Blanchett is the delicious and dangerous distraction. Dench’s sneaking admiration turns into a full-blown obsession. No one can deliver refrigerated malevolence quite like Dench, although the pleasure of being privy to her thoughts begins to pall with every revealing detail of her slight and pathetic life.

Blanchett’s infatuation with a 15-year-old boy is the rusty hinge of this black comedy. Dench, initially horrified by the discovery, uses the guilty secret like a grappling iron. She climbs into every corner of Blanchett’s crumbling family life. She is Blanchett’s ball and chain, but the daffy woman is too self-absorbed to read the runes. Bill Nighy is marvellous as the despairing husband who can’t fathom his wife’s crazy behaviour. But the real thrill is watching Blanchett and Dench at each other’s throats.

Richard Eyre directs the film like a chamber play. He leans on Philip Glass’s ever-present and insistent music like a crutch. But his natural gift for framing scenes is terrifically assured. A potent and evil pleasure.

Where is Notes on a Scandal on near me? Find out times for your nearest cinema in What's On

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010