Dennis Edwards

Steed and Cathy turn to practical jokes to discover who is conjuring with the Stock Market and why a man ate diamonds.

Leela is concerned by the Doctor's strange behaviour when, after a secret meeting with aliens, he returns to Gallifrey and abruptly stakes his claim on the Time Lord presidency.

The Doctor has betrayed his own people and enabled a Vardan invasion of Gallifrey. Leela joins forces with the Outsiders and prepares to strike back against the aliens.

The Doctor is made president of the Time Lords and immediately orders K9 to lower the planet's defences and has Leela banished to the wilderness.

After relaxing at a Roman villa the Doctor is mistaken for a murdered lyre player and targeted by an assassin. Meanwhile, Ian and Barbara are captured by slave traders.

Captain Tempest becomes involved when he sees a printer shut down for spreading stories of corruption amid the government. Tempest thinks there is some truth behind the story and decides to make a stand.