The Face of Evil - Plot

Plot

The Doctor, travelling alone in the TARDIS, arrives on a jungle planet and encounters Leela, a savage from the local tribe, who denounces him as the Evil One of fable amongst her people. She has been exiled from her tribe, the Sevateem, for profaning their god Xoanon who is kept prisoner by the Evil One and his followers, the Tesh, beyond a black wall. He speaks to them through the tribe’s shaman, Neeva. Now Leela is an outcast beyond the invisible barrier around her tribal home. Neeva has sent two men to murder her, witnessed by Leela's friend Tomas, who kills one of them as Leela dispatches the other. The Doctor finds a sophisticated sonic disruptor which creates the forcefield that keeps the creatures from attacking the village. The Sevateem will launch an attack on the domain of the Tesh to free their god, led by the combative Andor who suspects Neeva of being a false prophet, and Tomas tells him of Neeva's assassination attempt against Leela. Still, Andor believes the attack will succeed and is prepared to go ahead.

Two warriors are scouring the jungle when they find the Doctor, making a protective hand gesture which the Doctor interprets as the sequence for checking the seals on a Starfall Seven spacesuit. The warriors seize the Doctor. Leela manages to free him by using poisonous Janis thorns, which paralyze, then kill the victim. The Doctor is horrified by this and instructs her "No more Janis thorns, Ever". The pair flee the village to a clearing beyond where carved into a mountain nearby is an impression of the Doctor's face, who cannot recall why his face is depicted so. In Neeva’s holy tent, the Doctor inspects the ancient tribal relics, artifacts from an Earth survey expedition. He finds a transceiver used by Neeva to hear the commands of Xoanon. It speaks with the Doctor’s own voice, conveying exhilaration on hearing the Doctor that "At least we are here. At last I shall be free of us."

They head off to inspect the dark Wall at the entrance of the realm of the Evil One. The Doctor deduces it is a primitive time barrier, and is convinced the Sevateem warriors will be massacred if they attack the fortress of their enemy, the Tesh. From a distance they see the massacre unfold. Half the tribe is lost. Calib is first back at the camp where he finds the Doctor and Leela. He is intent on using the Doctor to break Neeva’s hold on the tribe by exposing the faith in Xoanon as misplaced mythology. Leela’s friend Tomas arrives and find Calib has stabbed Leela with a Janis thorn to prevent her exposing his schemes. The Doctor gets Tomas to help him move Leela to Neeva’s tent, where he uses a bio-analyzer to synthesise an antidote.The Doctor, Leela and Tomas address the tribal elders in defence of their lives. Calib intervenes to suggest the Doctor is not the Evil One, and this can be proven by getting him to take the fabled Test of the Horda, a pit full of two-foot-long worms which hunt in packs and react to the movements of their prey, stripping flesh from a man in an instant. The Doctor is given a crossbow which has to be fired at the exact moment to sever the rope without causing him to fall into the pit – which is the fate of the guilty. The Doctor succeeds so is presumed to be a non-malign influence and freed. He examines some relics of the tribe and repairs a disruptor gun. He tells some of the tribe the Sevateem are the descendants of a “survey team” which left a Starfall Seven Earth colony ship. The Doctor and Leela go to examine the face, climbing into it by scaling the Doctor’s teeth. Neeva in his tent is told by Xoanon the tribe will be destroyed, and the mysterious being then causes the sonic disruptor to shut down. These descend on the village, crushing Andor to death. Tomas uses the disruptor gun built by the Doctor to expose the true appearance of the invisible beings.

Leela and the Doctor notice a figure in a space suit in the “mouth” entrance and follow it through a projection of a wall. Beyond is a rocket, which the Doctor recalls as belonging to the Mordee Expedition, his memory of earlier events now returning. Xoanon has detected the Doctor nearby, and when he reaches the ship the god-creature is both ecstatic that "We are here” while also manically pledging that "We must destroy us." The Doctor and Leela meet three representatives of the Tesh, who serve and worship Xoanon. The Doctor deduces both Sevateem and Tesh are descendants of the same crew from the Mordee Expedition, with the Tesh (or technicians) involved in the same deadly eugenics exercise as the Sevateem (or survey team).

The invisible creatures that attacked the Sevateem are part of the same deranged scheme: Xoanon is a computer, designed to think independently. The Doctor had once repaired Xoanon but forgot to wipe his personality print from the data core, leaving the computer with a split personality. The Doctor, speaking as Xoanon with the communicator, instructs Neeva to tell Calib, who is now tribal leader, to lead the Sevateem survivors through the mouth of the face. With Leela keeping guard and holding the Tesh at bay, the Doctor ventures into the computer room of the ship to confront Xoanon. When Xoanon refuses to shut itself down, it channels a vicious mental assault at the Doctor, causing him to collapse, while Xoanon booms: "Who am I?"

Leela rescues the Doctor from the mental assault, and as he recovers he warns her of Xoanon’s power. Moments later they realise the computer has electrified the walls to try to kill them, and the Tesh become more purposeful in tracking them down within the spaceship. The Tesh also come under attack from Calib, Tomas and the survivors of the Sevateem, who now reach the spaceship too. This diverts the Tesh while the Doctor and Leela return to the computer room, where Xoanon briefly takes control of Leela’s mind. Most of the Sevateem come under the telepathic control of the computer too. The Tesh and Sevateem soon converge on the computer room too and interrupt the Doctor as he tries to repair Xoanon, realising the computer has now triggered the countdown to an atomic explosion. Elsewhere in the ship Neeva is alone but crazed, his faith in Xoanon shattered. The shaman uses the disruptor gun against one of the images of Xoanon/the Doctor projected through a wall. The ensuing blast kills Neeva but also interrupts Xoanon’s control of its subjects, allowing the Doctor to resume and complete his repairs. Xoanon’s circuits explode, knocking the Doctor out.

Two days later the Doctor wakes up to find himself aboard the spaceship in the care of Leela. She explains Xoanon has been quiet and he interprets this as success for his extraction experiment. They visit the computer room and find Xoanon’s identity and sanity restored. The computer confirms it was running a eugenics experiment and thanks the Doctor for his repair work. The Doctor then contacts the survivors of the Tesh and Sevateem and tells them Xoanon is now cured and able to support their new society. He then heads off to the TARDIS followed by Leela. She insists she join him on his travels, and when he refuses she jumps into the TARDIS with him and starts the dematerialisation process.