The
Sixth Doctor and
Peri find themselves being threatened by Anzor, an old school bully from the Doctor's time on
Gallifrey, who locks the TARDIS in orbit above the planet of Magnus. On this planet, Anzor has been working with the female upper caste to his own ends, alongside the Doctor's old enemy
Sil. When the Doctor investigates further, he discovers that the polar icecaps of the planet hide an even darker foe — the
Ice Warriors.
