In a society recently plagued by sink holes and the trolls that are causing them, the divide between changelings and civilisation seems ever wider. Sixteen-year-old Maurice is of the firm belief that anti-social behaviour is not really a sign of youth culture, it is the mark of a troll - a troll swapped at birth for a human child. A school excursion to The Dregs - a sinkhole estate where Changelings are sent if they are discovered - is not Maurice's idea of fun. Neither is the hijacking of of the school bus by a gang of riotous trolls. Being kidnapped by said trolls, just about puts the icing on the cake. But salvation comes in the unlikely form of Wretch, a teenage troll with a heart of gold but a head for destruction.