Doctor Who - Season 21 (1984)

With Silurians in control of the base, Icthar reveals his plan for a final solution to Earth's human problem, which presents the Doctor a great moral dilemma.

The TARDIS arrives in Little Hodcombe. Tegan wants to visit her grandfather, only he's disappeared. There's also a war game going on, and it's getting out of hand.

The Malus, an alien that's purely evil, needs the civil war re-enactments to become authentic so it can feed off the psychic energy of dying and embattled men and fully revive. Not if the Doctor can derail things, of course.

In the far flung future, the TARDIS is forced to crash land on the planet Frontios, where the Doctor finds some of the last surviving human beings cowering from a meteorite bombardment.

Following the destruction of the TARDIS, the only part of it left is the hat stand. So Turlough uses it as a weapon! Plantagenet gets swallowed by the earth, and Norna and Turlough discover the Tractators.

Trying to rescue the Doctor from the Tractator's trap, Tegan finds herself and the Doctor in even more trouble. Turlough goes a bit mad, and reckons he knows the evil of the Tractators from old.

The Doctor tries to deal with the Tractator's cunning plan, despite Turlough's best intervention. They discover the splintered TARDIS in the tunnels beneath the planet's surface, but how will they put it together again?

A time corridor forces the Doctor to the London docklands on present-day Earth where a bomb squad watches over some strange, alien canisters. At the other end, a battle cruiser lunches an assault on a prison space station that holds just one prisoner - Davros, creator of the Daleks.

While Davros looks into solving a small problem offered up by the Movellans, the Daleks have not overlooked the Time Lords for all their years of interest and attention paid them, hoping to make of the Doctor and his companions emissaries of their appreciation, in order to thank them all to the fullest and permanently.

The Doctor and Turlough arrive on Lanzarote to investigate a signal. Turlough rescues American Student Peri Brown from nearly drowning and discovers she has in her possession a data core from Turlough's home planet Trion. The Doctor, Turlough and Peri follow the signal to the volcanic planet Sarn, where the natives worship a fire god known as Logar, and where the Doctor learns The Master has accidentally shrunk himself after testing a more lethal version of his tissue compression eliminator and has taken control of Kamelion, using him to find numismaton gas that will ...

On the volcanic planet Sarn, Turlough recognizes several Trion artifacts that point to Malkon (the Chosen One among the Sarn people) being his own brother. Meanwhile, Peri flees from Kamelion who has almost been entirely possessed by the Master.

Sarn prophesy foretells of an outsider who will come to aid the people. It's a role the Master is more than delighted to fill, which finally presents Timanov, the Sarn religious leader, the unbridled support he's sought in his campaign to cull the faithless from among his people. Turlough's secret past, however, is somehow intricately involved in all this, and the reluctance of its disclosure is enough to threaten all friendly ties with the Doctor.

While the Master, victim of his own attempt to improve his TCE weapon, seeks restoration through Sarn's numismaton gas, the truth of Turlough's past comes out at last, though to guarantee the safety of his brother and the Sarn people, Turlough must consider a great personal sacrifice.

The Doctor and Peri get involved with drug running after landing on the twin planet of Androzani Minor and getting arrested as gun runners and targeted for execution. Not before Peri stumbles into some highly toxic and lethal plant life.

Having been saved from execution by Sharez Jek and his androids, Jek takes a shine to Peri, and wants her with him forever. Salateen tells the Dr and Peri that they are dying from Spectrox toxemia, but there is an antidote.

After escaping the vicious Magma creature, the Doctor is made a prisoner of the gun runners and taken to Androzani Major. The real Salateen takes an ill Peri back to Chellak.

Chellak and his men attack Jek's base. The Dr. crash-lands the ship, and must escape from his captors to find the antidote to the Spectrox poisoning and save Peri. He does so, but at a staggering cost.

The Doctor's moods are wide and in a jumble as he settles into his new regeneration. Elsewhere a set of genius twins are kidnapped, whose mathematical computations can manipulate features of the universe. They're immediately put to work by aliens for an as yet unknown end.

The Doctor takes Peri to Titan 3, a desolate hunk of rock in space where he hopes to find some solitude for awhile. Instead he finds the lone but unconscious survivor of a recent spaceship crash in sight of a mound-shaped complex where no formalized structure should exist.

The Doctor arrives on Jaconda, once lush and green, to find it completely devastated by giant gastropods. Old legends about the planet's half-human/half-slugs weren't just myths after all. With or without help from the Doctor and his unpredictable mood swings, Lt. Lang is up for rescuing the twins, who are finally informed of the grand purpose they've been brought to Jaconda to accomplish.

The Doctor and Edgeworth deduce that the real plan of Mestor, the gastropod ruler of Jaconda, will not only destroy Jaconda but lead to the devastation of other planets. Together they hope to thwart him despite his formidable ability at slipping into people's minds and controlling them.