Our Precious Lulu, By Anne Fine

The term stirrer, meaning someone who deliberately causes trouble, now has a definitive reference-point in a literary character, with the beautiful Lulu, younger step-sister to the less glamorous Geraldine: mean-minded as a child and intolerable as an adult. Never expressing her aggression openly, she is mistress of the "innocent" faux pas and the cutting aside.

Fatally, Lulu is encouraged in these black arts first by her adoptive mother's weak compliance and then by her older sister's maddening passivity. Poor Geraldine's lifetime attempts at neutrality merely stimulate further aggression.

Freud's theory of reaction formation states that those who come out most strongly in one personality direction generally hide feelings that are exactly the opposite. On this basis, hostile self-confident presences like Lulu are concealing a deep insecurity. While this formula should make it easier to forgive gross social transgressions, whether in life or in fiction, anger is still the usual result.

So the moment when Geraldine, in a Jane Eyre-type outburst, at last denounces her younger sister should have every reader punching the air. But, as always in good novels, things are never quite as they seem. Is the girls' mother most to blame for bending so far backwards to appease the troublesome Lulu, who came into the family from different parents? As Geraldine puts it to her, parents "don't neglect their children because they dislike them. They dislike them because they neglect them."

Geraldine's seemingly endless capacity for taking knocks sometimes threatens to become tedious. But Anne Fine is too canny a novelist to risk losing her readers for long. Geraldine and her incredibly patient husband talk to each other about Lulu with the blackest of humours, each complaining word – and no writer uses italics to greater effect – another dagger wielded in this rich feud. Best read after rather than before any extended-family event, this wickedly entertaining novel, with its unexpectedly happy ending, is not one to miss.