The place is St Oswald's, an old and long-established boys' grammar school in the north of England. A new year has just begun, and for the staff and boys of the School, a wind of unwelcome change is blowing. Suits, paperwork and Information Technology rule the world; and Roy Straitley, Latin master, eccentric, and veteran of St Oswald's, is finally - reluctantly - contemplating retirement. But beneath the little rivalries, petty disputes and everyday crises of the School, a darker undercurrent stirs. And a bitter grudge, hidden and carefully nurtured for thirteen years, is about to erupt.

Who is Mole, the mysterious insider, whose cruel practical jokes are gradually escalating towards violence - and perhaps, murder? And how can an old and half-forgotten scandal become the stone that brings down a giant?