Cambridge is home to 18,000 students, 1,500 academics - and one serial killer. The discovery of the headless, mutilated body of a female undergraduate in her bloodsoaked college room heralds the start of a series of bizarre and extremely violent murders. For the students of Ariel College, a siege mentality has developed following weeks of media interest in the 'Cambridge Butcher'. University life has become not about surviving their exams, but surviving full stop.

Forensic psychiatrist Matthew Denison is sure that his traumatised patient, student Olivia Coscadden, has the killer's identity locked up in her memory. That within the little clique she belonged to lurks someone with a grudge. Someone who has yet to finish settling their score.

In order to get to the truth, Denison must delve into the secrets hidden within Olivia's subconscious. Secrets that are about to lead him into a nightmare beyond imagining.