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.
At Brendon School, the Doctor enlists the help of the Brigadier. At Brendon School, Tegan enlists the help of the Brigadier. Same man, different time periods, however.
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.
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.
Steed and Cathy turn to practical jokes to discover who is conjuring with the Stock Market and why a man ate diamonds.
