Bedfordshire Police's largest ever operation into historic abuse continues, with DS Rachael Foy spending three years working to persuade victims to testify against the suspect. However, she knows that the system too often lets victims down even when they are brave enough to come forward - and in this case, many of the victims have died before they are able to do so.

The real-life drama follows police investigations into one of the most disturbing and hard-to-prove crimes - baby-shaking cases - and examines parents' often-divided loyalties.