The Doctor endeavors to prevent the re-existence of a Fendahl, a group entity that feeds on life itself and thought only to exist in Time Lord mythology, but a witches' coven, seeking power, intervenes.

The Tardis lands on Pluto in the far future. Instead of being a lifeless rock, there's scented air, massive buildings, six suns, a human population subjugated by crippling taxes from a government called "The Company," and a man about to commit suicide.