Gallifrey is under attack by the Knights of Velyshaa, while a time distortion traps the Seventh Doctor on a prison planet, the Fifth Doctor on a WWI German u-boat, and the Sixth Doctor on a devastated space liner.
1702. London. The Doctor and Turlough become part of a plan by gambler Sir Nikolas Valentine, a member of the enigmatic Diabola Club. Who is he and where does the mysterious highwayman that roams the streets fit in?
The Doctor and Peri visit the Museum of Aural Antiquities, where every sound is stored for posterity. and discover an intruder, mysteriously changed recordings, and a dead body. There is more going on here than a simple break-in or murder.
