The UCOS team investigate the murder of a young peace protestor, killed at the outskirts of a nuclear base in 1984, and realise that they may be in danger of exposing a Special Branch cover up.

When a missing person case which Lane originally investigated gets re-activated, he's determined to crack it. But when the team swiftly uncover another two mysterious disappearances, they start to think they've got a serial killer on their hands.

In an attempt to make contact with his late wife Mary, Jack goes to see a clairvoyant. Instead he meets a girl who died in a shipping container in 1982 and has the case re-opened.