All the elements of an enjoyable read turn up for reunion.

Byline: By Peter Robins

Past Mortem by Ben Elton

(Bantam Press, pounds 17.99)

Contrary to what they say on the back of thrillers, it's quite easy to get inside the mind of a psychopath. You don't have to bother with empathy.

All you need is a gimmick and a childhood trauma to explain it. Add eccentricities and academic qualifications to taste. Ben Elton stops after the childhood trauma, which is a sign of his professionalism: the killer is hard to spot in Past Mortem because he's no more interesting than anyone else.

The gimmick is pretty flashy, though. Someone is murdering former school bullies, torturing them at length to the sound of nostalgic compilation CDs. Meanwhile, the investigating officer ( short and ginger, but with a better school experience than you might expect ( is himself becoming obsessed with Friends Reunited.

Elton is as alert as ever to the fictional potential of news topics: to bullying and the side effects of Friends Reunited, add a Bransonesque businessman and digs at the possible extension of London's congestion charge area. And at least one of the deaths has echoes of a real case.

Once you've spotted the references, however, there's not much to detain you.

The construction is efficient but the detail of the writing is often slapdash ( for a book in which childhood brutality is meant to be the driving force, Past Mortem conveys remarkably little of the texture of being at school.

Instead comes a sense of cynicism: the characters feel like an excuse for violence, sex, two or three good gags and a romantic subplot rather than the reason for them.

Yes, all the elements of an enjoyable read have turned up for the reunion.

The booze is pressed upon you and the small talk rattles along. But you're likely to leave feeling queasy ( and by the morning, there may not even be a hangover left.