4Q4 - The Face of Evil 4

Towards the end of this story, Xoanon sends out a distress signal to his servants, Tesh and Sevateem alike, to attack The Doctor before the Time Lord destroys the schizophrenic computer. All his servants obey and fall into a trance, returning to the control room to kill The Doctor. Even Leela, whose mind is becoming open to the world around her, thanks to The Doctor's influence, falls under Xoanon's trance.

The only person who is immune to Xoanon's power is Neeva, whose desire for revenge against Xoanon is so strong that destroying his god has become Neeva's single overriding thought. When the Tesh and the Sevateem are about to kill The Doctor, thanks to Xoanon's power over his servants, it is Neeva's individuality coming through in the form of an attempt to destroy the god that breaks Xoanon's hold over his servants long enough to allow The Doctor to wipe his memory print clear from the computer.

Neeva and Tomas had a notable exchange earlier in this episode while assailing the Tesh ship. At the time, Neeva had faith in his beliefs, and admonished the rest of the tribe that they were losing their belief in the search for proof. Tomas replies with one of the many, many great lines in this episode: "With proof, you don't have to believe." And once Xoanon was proven to be a false god to Neeva, only then could he be destroyed.

Often overshadowed by the leviathans that surround it in the Season 14 running order, The Face of Evil is one of the more densely layered Doctor Who stories ever made. it is also thoroughly enjoyable, and, at the time of writing this, quite overdue for a DVD release.