Caseys Unit is, as ever, full of troubled, disaffected pupils, and new arrival Leo is something of a conundrum.

Thirteen year old Leo isnt a bad lad in fact, hes generally polite and helpful, but hes in danger of permanent exclusion for repeatedly absconding and unauthorised absences. Despite letters being sent home regularly, his mother never turns up for any appointments, and when the school calls home she always seems to have an excuse.

Though Casey has her hands full, she offers to intervene for a while, to try get Leo engaged in learning again and remaining in school. The heads sceptical though and warns her that this is Leos very last chance. But Caseys determined, because theres something about Leo that makes her want to fight his corner, and get to the bottom of whatever it is that compels this enigmatic boy to keep running away. With Leo so resolutely tight-lipped and secretive, Casey knows that if shes going to keep this child in education, shes going to have to get to the bottom of it herself