The Time Lords of Gallifrey need no introduction, surely! Capable of regeneration (sometimes more than) 12 times for a total of 13 lives across potentially thousands of years, The Time Lords harnessed the power of the Eye of Harmony to grant them dominion over nature as over time. Most famous among them, arguably, is of course The Doctor.
The Doctor and Lucie battle bionic centipedes, face the Sisterhood of Karn, and must stop the regeneration of Morbius.
The Doctor, Vicki and Steve arrive in England in 1066 and are pitted against Saxon logic, brutal Vikings and a fellow time traveller.