The Doctor and a newly-regenerated Romana arrive on Skaro to find that the Daleks, locked in a war with the robotic Movellans, have returned to retrieve their buried creator Davros.

After the TARDIS collides with a spacecraft delivering human tributes to the evil bull-like Nimon, the Doctor and Romana must stop the fearsome alien's quest to rule the galaxy.

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?