BOOK REVIEW / Nuclear family fall-out: Before and after - Rosellen Brown: Hodder, pounds 14.99

OBSERVE the nuclear family as it detonates. One day paediatrician Carolyn admits the corpse of a teenage girl with bludgeoned skull into the hospital casualty department. That night, she and her sculptor husband Ben calmly open the door to their police-chief friend to discover that their son Jacob is under suspicion for the girl's murder. Their Jacob?

Where is he anyway? What is that wet stuff on the jack in the car boot? Why is Ben dementedly destroying 'evidence' before anyone has had time to rebound from the first shock? As moral mazes go, Rosellen Brown has set a real stinker for the Reiser family - and for readers. Ben is driven by blood loyalty to protect Jacob no matter what he has done. His own Jewish father believed there should be an 11th commandment: 'Honour thy children.' A rabbi has explained that in Jewish law parents need not testify against their children. Unfortunately, New Hampshire law doesn't see it that way and Ben spends six months in jail for contempt of court even before Jacob's case comes properly to trial.

Pity the poor lawyer with defiant Ben on one hand and Carolyn, having a crisis of conscience on behalf of the victim's family, on the other - and neither of them consulting him before mouth-off. With inimitable legal logic the lawyer tries to explain: 'Carolyn, screw what really happened. The truth in a courtroom is just a construction of effects. It's theatre . . . ' But Carolyn has seen too many truth-will-out movies, and tended too many injured children, to prove other than a very loose cannon for the defence.

More revealing than Carolyn's high-mindedness is her 12-year-old daughter's view of the dark side of Jacob: glimpses of cruelty, sexual precocity. Not that he's a monster, but then not all murderers are - just as not all monsters are murderers. Can luck actually play a part in acts so irreparable? Judith shares her mother's aversion to lies, but who wants to be an avenging angel?

There is a minimum of actual courtroom drama but, as the lawyer says, that's not where you look for the truth anyway. As was apparent in her excellent novel Civil Wars, Rosellen Brown is an avid student of the ethics of crisis. Her focus here is on how you get from one day to the next in hell - and her realism makes your eyes water.