The planet Peladon, some time in the future. The Doctor and Jo arrive just in time to get involved in the conference to discuss Peladon's admission to the Galactic Federation. But the King's closest counsel has been murdered, apparently by a ghost... and then the Doctor learns his old enemies, the Ice Warriors, are also attending the conference...
Elenco: William Hartnell , Patrick Troughton , Jon Pertwee , Tom Baker , Peter Davison , Colin Baker , Sylvester McCoy .