A special edition Lethbridge-Stewart short story in celebration of the 50th anniversary of BBC Radio 1. The BBC One Roadshow is in town, but Lethbridge-Stewart isn’t one for leisure. A rogue analyst has discovered the threat of an alien invasion encoded in the lyrics of pop hits. With the festivities beginning, and fifty-thousand revellers in attendance, the Brigadier must get to the bottom of the mystery before musical mayhem is unleashed.