Season 19 - Episode Guide

The Doctor has regenerated but it hasn't gone well. He's mentally unraveling and needs a place to rest beyond outside influences. Unfortunately the Master has laid a trap for the TARDIS that denies the Doctor undisturbed recovery time.

To avoid falling into Event One (the Big Bang), the Doctor must convert mass into momentum by having the TARDIS jettison a quarter of itself. Unfortunately it can not be known which rooms will be ejected.

The city of Castrovalva and its untroubled people would seen an ideal place for the Doctor to recover, but a dire warning from Adric, held captive by The Master, makes it seen less so.

The Doctor discovers Castrovalva is a cursive occlusion, an impossible yet manifested Escheresque environment, with all pathways, no matter which direction one goes, leading back to the same point. It is a trap laid by the Master with no apparent way out.

The arrival of the TARDIS is observed by three Urbankans via their manipticon devices. Intrigued, they begin dividing the Doctor's friends, and disguising themselves as humans.

As the Doctor meets the representatives of humanity aboard the Urbankan ship, a Grecian philosopher reveals a bizarre secret about Monarch and his methods.

Panicking, Tegan accidentally pilots the TARDIS into space, while Lin Fitu betrays the Doctor and Bigon to Monarch, who demands they be beheaded as punishment.

The Doctor takes a dangerous spacewalk to rescue Tegan, while Nyssa and Bigon keep the Urbankans distracted and Adric decides exactly whose side he is on.

On Deva Loka, a sylvan paradise planet with no predators, diseases or civilized roadways, Nyssa (due to Monarch's two attempts to turn her into an android) stays in the TARDIS to fully recover from mild mental disorientation, under the Doctor's Delta Wave Augmenter while the others go exploring. The Doctor and Adric find a survey team assessing the planet for colonization, and cracking under the stress of three fellow members (half the crew) disappearing without a trace. There's also a primitive and almost entirely speechless native culture on hand who curiously have about them a few items of technically advanced skill and knowledge. Meanwhile Tegan succumbs to a dreaming tree where an evil entity awaits a catalyst for entering the real world.

Left in charge by Sanders, Security Man Hindle - unhinged and in complete control of the two Kinda hostages - locks up the others while he primes the dome for a 50 mile perimeter of deforestation through acid and fire, having "reasoned out" that the trees and plants are a threat. Adric perpetrates a ruse to help the Doctor and Todd but is caught and about to be punished when Sanders returns, a changed man. Sanders bears a gift for Hindle - a box given him by a Kinda mystic elder, which may be dangerous and which the Doctor is forced to open. Meanwhile, Tegan is shown herself in the dream world and left to determine which of her selves is real.

Todd and the Doctor receive a telepathic invitation to visit the Kinda's blind matriarch and her ward in a cave. Meanwhile, Hinkle is finally set to reduce the dome to its "base chemical constituents" but stops to relax and build a toy city. Tegan is out cold after the snake tattoo of the Mara leaves her arm to possess Aris, giving Aris voice and, through it, the ability to lead his people to their destruction.

With a frightening vision of what's to come from Panna (the Kinda's blind visionary), the Doctor must break Hindle's control over the Kinda hostages and stop his deforestation plan, then send the Mara back to The Dark Places of the Inside from whence it came before it can destroy the Kinda and head out to topple civilizations.

The TARDIS returns Tegan to Heathrow Airport: Tall trees, peaceful, clear skies, thriving vegetation and a touch of sulfur in the air. Obviously the TARDIS is a little out of date (about three hundred years or so), but upon looking around the Doctor finds there's more amiss than his navigational controls, all arising after a recent comet crash that was not on Earth's schedule.

To rescue Tegan and Adric, captured and interrogated by the Terileptil fugitive leader, the Doctor must get past the locals under alien control and overcome Death (an android servant dressed up as The Grim Reaper).

The Doctor makes the fugitive Terileptils a rare offer they shouldn't refuse; but, though few in numbers, they have a plan in the works for the quick and complete domination of Earth and mean to see it through.

With Tegan and Richard under alien control, and the manor sealed against anyone leaving or entering, it's a question whether or not the Doctor can get to London before the Terileptils release their improved strain of black death upon the world.

A murder is committed in Cranleigh Hall .The Cranleighs ask the Doctor to play cricket and then join them for a masked ball, enabling the killer to hide in plain sight.

The Doctor stands accused of murder, despite Lady Cranleigh knowing he is innocent. What is the secret she is protecting that allows her to let an innocent man go to jail?

The Doctor lands the Tardis in an underground cavern on 26th century Earth. Then the Doctor, Tegan, Nyssa and Adric become embroiled in the search for a team of missing scientists being preformed by the military.

The Doctor discovers a bomb planted by the Cybermen, disarms it and then materializes the Tardis onto a freighter orbiting the Earth where mysterious murders are also being committed.

Captain Briggs takes the Doctor prisoner, suspecting him of being behind the murders on board. Meanwhile the Cybermen start the process of taking over the ship with the help of a traitorous crew member. The Cybermen also start reviving other Cybermen who are hidden away as cargo.

The Cybermen have taken over the bridge of the freighter. They fit a device onto the freighters control panel that will cause the ship to explode. The ships fuel will cause a explosion so strong that it will destroy the Earth completely. The Doctor and Companions battle against the Cybermen in an attempt to foil their plan. Someone pays the ultimate price to save the Earth and crew of the freighter.

The Doctor still dealing with Adric's death, lands the Tardis at London's Heathrow airport and soon becomes involved with a missing Concord SST.

The Doctor's Tardis vanishes, while tracking it down the Doctor encounters a strange being named "Kalid" who seems to be in control of events.

The Master commandeers the Doctors Tardis, leaving the Doctor behind to figure out what the alien artifact is.

The Doctor partially works with The Master, the crew of the Concord jury rig the plane so they can take off with the Doctor's help. The Doctor follows The Master back to Heathrow airport. The Doctor announces that the temporal limiter The Master conned him out of will need replacing and that he is going to be stuck. Tegan gets accidentally left behind at Heathrow.