Last in the series for this cold crimes case squad sees them tackle an unsolved murder from back in 1983, when 16-year-old Amy Taskerland was found dead on the night of the school disco. More than 30 years later, the unearthing of a time capsule and the discovery of her voice on a mix tape inside prompts Miller and the gang to delve back into the case, starting by interviewing Amy's best friend Harriet and her former teacher Mr Hines. Strangely, the recording features words from a speech written for the Queen for broadcast in the event of a nuclear war. Just how in the hell did Amy get a hold of that, and was that somehow linked to her murder?