For Peter 'Mad Max' Maxwell, the only mystery that has arisen so far this year at Leighford High is the question of how to use a computer.
The 'dinosaur' Head of Sixth Form just cannot get to grips with technology, and doesn't see the need to know how to send a text or an email, when a simple note or phone call will suffice.
However, it soon becomes vital that he learns when some of his female pupils begin to receive strange and threatening messages, with the anonymous sender claiming to know intimate details about the girls' personal lives.
Then Max starts to receive messages too, and two of the girls go missing.
When a body is found it seems that the prank has taken a sinister turn. And Mad Max may well be the next target. With his job under threat from the ambitious IT technician, Nicole, and the formidable Pansy Donaldson, as well as facing increasing pressure from his wife to retire, will Max manage to crack the case? Or is the chance of him reaching retirement looking more unlikely by the day?