UCOS want to talk to a Turkish girl who is found working illegally in Dalston, regarding a unsolved murder from 2009. The landlord of a pub, Richard Gibson, died in a fire and the case had remained unresolved. The team meet the landlady of the pub, Joanna Gibson, who is also Richard's widow. His best friend, David is also someone of interest, especially when the team find out the French champagne he is selling, is actually sparkling wine produced in Britain. Sasha enters the team into a 5-a-side football competition.

A mix tape from 1983 is discovered, containing the voice of a teenage girl who was murdered shortly after it went into her school's time capsule. Griffin becomes convinced that the girl is reading from a speech secretly prepared for the Queen to broadcast in the event of a nuclear war.

Meanwhile Sasha is distracted by a romantic entanglement with a charming record shop owner and Gerry is dreading his future son-in-law Robin's stag night, which promises to be something very special...