The Doctor and his companions arrive on a spaceship headed for Earth, populated by natives of Earth from various different eras and commanded by the leaders of the Urbankan race. What are the Urbankans' intentions when they reach Earth?
| Actor | Role |
|---|---|
 Peter DavisonThe Doctor | The Doctor |
 Matthew WaterhouseAdric | Adric |
 Sarah SuttonNyssa | Nyssa |
 Janet FieldingTegan Jovanka | Tegan Jovanka |
 Stratford JohnsMonarch | Monarch |
| AAnnie LambertEnlightenment | Enlightenment |
 Paul ShelleyPersuasion | Persuasion |
 Philip LockeBigon | Bigon |
| NNadia HammamVillagra | Villagra |
 Burt KwoukLin Futu | Lin Futu |
| IIllarrio Bisi PedroKurkutji | Kurkutji |