Rupture, By Simon Lelic

A brassed-off history teacher, Samuel Szajkowski, walks into a secondary school assembly, shoots three children and one teacher dead, and kills himself, using an antiquated revolver. The first we hear of it in Simon Lelic's arresting debut is in the account given to the investigating inspector, Lucia May, by a feckless and garrulous lad who wasn't even on the premises at the time.

This account (in which, as in tmany subsequent statements, May's contributions are cleverly omitted) is immediate evidence that Lelic has an exceptional talent for voice. This talent means the reader is yanked into the narrative, and teased into persisting. It's true that the unvarying pattern of the novel – a succession of 15 "'monologues" interspersed with May's experiences – is risky. You could say that 15 voices is too ambitious; that it is impossible to distinguish them; that the structure leads to a degree of predictability. Yet Lelic pulls this off, each speaker helping the reader puzzle out what has happened and, more importantly, why.

You can read Rupture as a whydunnit, but it is a novel, above all else, about bullying: mental and physical torment. It's not just that there is a parallel case at the school about a boy assaulted for having ginger hair and a birthmark. May herself is bullied throughout, by her so-called colleagues, and by her boss (who has more than a touch of Mullet, as in Frost, about him).

The children, teachers, parents and others who take us slowly closer to what has been done to Szajkowski, and why, live in a world of casual psychological violence. Their sheer self-absorption is what makes this novel so startling, so dark. If it is foreseeable that we will wind up siding with the killer, the process of shifting our allegiance is subtle and constant.

Lelic faces two tasks more difficult than building the narrative structure. The first is to avoid stereotyping some of the characters. The lecherous detective who invades May's space, and the headmaster of the aspiring school, come perilously close to being caricatures. The second is to leaven a brutal progress with bitter humour. No problems here: Lelic has a perfect ear for the wayward manner in which May's witnesses carelessly blurt out their self-aggrandising accounts. The horrible description of a football match between the staff and pupils, a brilliant set piece, is grimly entertaining.

Lelic can write like a poet – a doctor's jaw tightens so that it looks "as though he were attempting to swallow a screwdriver". The novel is full of these crackling images. The pace is as ferocious as the subject, and some characters – notably the PE teacher who corrupts or calcifies every person with whom he has contact – are expertly grotesque. Lelic's novel may be his first; but you wouldn't know it, it is so controlled, yet confidently reckless.