"Serena Frome, the beautiful daughter of an Anglican bishop, has a brief affair with an older man during her final year at Cambridge, and finds herself being groomed for the intelligence services.
The year is 1972. Britain, confronting economic disaster, is being torn apart by industrial unrest and terrorism and faces its fifth state of emergency."
Serena seems a strange recruit to "Five". She has a third from Cambridge, where she took maths under her mother's formidable influence (she'd wanted to study English at Leicester) and she's emotional, naive and immature.
This is 1972 and women in MI5 toil in menial clerical jobs. But Serena is attractive and a novel-junkie, so who better to liaise with suitable up-and-coming authors in a covert MI5 funding operation (Sweet Tooth) fighting the communists in the culture wars. But for Serena, everything is personal: there is no way this is going to end well.
Ian McEwan has written another inspired novel. It's not le Carre - not an intelligence-insider's novel - but the atmosphere is similarly insecure, no-one's motives can be taken at face-value.
McEwen effectively evokes the dysfunctional feel of the 1970s, when everything was going pear-shaped, but his most effective skewering is of the stupidity of the intelligence agencies themselves.
Oh, and the twist at the end is completely brilliant.