Peter Robinson invites Simon to Yorkshire, the setting for his successful DCI Banks series, where he reveals the largely untold story of 14-year-old Elsie Frost, who was fatally stabbed while walking home from a sailing lesson in Wakefield in 1965. She had had a choice between two routes home, and not wanting to get her new shoes dirty, she had walked the cleaner path; a path that played home to a killer. Elsie was found in a nearby tunnel having bled to death mere minutes prior to the discovery. The crime rocked the community, culminating in a mistrial after a local man was falsely accused. The case stayed cold for half a century, until an investigation into another crime led police to uncover evidence pointing towards Elsie's killer. As the investigation moved from Rotherham to Barnsley before concluding in Leeds, the episode journeys through many of the familiar landscapes that underpin every Peter Robinson book.