UCOS reopens the case of Amy Taskerland who died at her posh school over 30 years ago after falling - or being pushed - down some stairs. Now, the school has unearthed a time capsule which contained a cassette recording from Amy. The tape has degraded considerably but it's clear that she is frightened, constantly referring to someone named Alec. They review the files and re-interview those who knew her but no one has ever heard of anyone in Amy's life by the name of Alec. Danny however concludes that Amy recorded a speech that had been prepared for the Queen in the event of nuclear war with the USSR. Just what she was doing with such a highly classified document will lead the team to solving her death.
—garykmcd