When teenager Rosie Duff was found brutally murdered in the Scottish university town of St Andrews in 1996, suspicion fell on the three drunken students who were discovered at the scene of the crime, claiming to have found her body. But with a lack of forensic evidence, no charges were brought and the police investigation floundered.

Twenty-five years on, someone appears to be willing to risk everything to keep the secrets surrounding the case hidden. Do the three men know more than they previously revealed? How flawed was the original investigation? And can Karen uncover the truth of what happened to Rosie that fateful night?