Former police officer and DNA expert Dr Sian Love has settled into running her own detective agency and cohabiting with her partner, Kris. Then her life is thrown into chaos once again when a teenage girl shows up at her office, claiming to be Courtney Johnson - a child who went missing in Nottingham over 15 years ago - but refusing to allow Sian to test her DNA. Wary but intrigued, Sian reluctantly revives the undercover skills she learned in her days in the police force and begins investigating. But revisiting the past has consequences. . .