Criminal Classes — Cecilia Peartree

This is the 24th book in the Pitkirtly Mystery series. Clementine Fairfax, previously encountered in 'The Identity Illusion', returns to Pitkirtly under cover to investigate a computer crime which has been traced to Pitkirtly College computing department, where Zak Johnstone is currently studying. Two suspicious deaths later, she is not very much the wiser about what is going on. Meanwhile Clementine's half-sister Amaryllis gets into a tunnel again, Christopher and others try to find something positive in changes at the Cultural Centre, and Zak is doubtful about his future.