The English channel, the 1900s AD. The TARDIS lands on barren Fang Rock, inhabited until now only by three lighthouse keepers. But what is the strange fog covering the island, and can it be connected to the falling star sighted earlier that night?

The survivors of a wrecked ship are stranded with the lighhouse crew on Fang Rock as a deadly menace slithers through the fog. Has the Beast of Fang Rock returned?

The Doctor barricades everyone in the lighthouse to protect them from the mysterious deadly creature in the fog. But it may already be inside, biding its time…

The Rutan starts picking off the surviving humans one by one as the Doctor and Leela struggle to defeat not only the alien but an entire fleet waiting to occupy Earth.

Deep space, 5000AD. An Earth supply shuttle is infected by a strange sentient space-borne virus, which quickly spreads to the crew of the refuelling station on the moon Titan. Even worse, the Doctor himself falls victim. But why is Leela immune, and what is the virus's ultimate goal?

Leela and Lowe take the Doctor to the Bi-Al Foundation for help. But how can they cure an infection of the mind?

Miniaturised clones of the Doctor and Leela are injected into his brain. But they must now fight the virus on its own level. And its servants are closing in around them.

The Nucleus, now grown to human size, is determined to spawn and take over the Galaxy. Only the Doctor and Leela can stop it.

England, the late 1970s. At Fetch Priory, Dr Fendelman's experiments with the new Time Scanner are disrupted by the mysterious death of a hiker, nearby. Then there's the mysterious skull, also being used as part of his work. A skull that seems to predate the evolution of mankind. What is the true role of the Fendahl in humanity's evolution?

The mystery surrounding the strange skull deepens. Thea is slowly succumbing to its influence while the Doctor prepares to battle a creature from mythology.

While Max prepares to tap supernatural forces beyond imagining, the Doctor and Leela investigate the legend of the Fendahl.

The Fendahl is returning to life, ready to consume everything in its path. Can the Doctor find a way to kill death itself?

Pluto, the distant future. The planet has been terraformed and is now orbited by artificial suns, provided by the rapacious company who ruthlessly exploit the relocated human workforce. The Doctor, Leela, and K9 arrive and befriend a luckless drone worker, but they must flee with him to the dark undercity...

The Doctor has been captured by the Gatherer. Leela works to free him but the Gatherer is already laying his own plans…

Now Leela is the prisoner of the Collector. He knows of the Doctor and is determined to rid himself of both of them.

The Doctor now moves to completely overthrow the Company. But the Collector has one last trump card to play.

Deep space, an unknown time. The Doctor encounters the Minyans, survivors of a race the Time Lords unwittingly obliterated early in their own history. The Minyans are searching for their race's lost gene banks, a quest which takes them to the edge of the galaxy…

After 100,000 years, the Minyans have found the long-lost P7E. But what awaits them on the ship, long buried in the core of a newborn planet?

The Minyans have, at long last, found the P7E. But a host of guards and robotic seers stand between them and the race banks.

The Minyons struggle to gain the precious race banks from the Oracle. But perhaps it is giving in a little too easily ...

Gallifrey, world of the Time Lords. The Doctor returns and claims the vacant presidency. But his behaviour is erratic and his motives mysterious.

The Doctor is made president of the Time Lords. He immediately orders K-9 to lower the planet's defences and has Leela banished to the wilderness.

The Doctor has betrayed his own people and enabled a Vardan invasion of Gallifrey. Leela joins forces with the Outsiders and prepares to strike back against the aliens.

The Doctor works to free his planet of the Vardan menace. How can he defeat an enemy who can read his very thoughts? And does their invasion conceal a greater menace?

The Sontarans have invaded Gallifrey, seeking to seize the incredible power of the Time Lords. The Doctor's first step is to cut them off from their fleet. But Kelner is helping the enemy…

The Sontarans finally invade the TARDIS itself, seeking the Great Key. The Doctor, however, has other uses for this powerful object…

The Magellanic Clouds, the planet Ribos, an unknown time. Ordered by the White Guardian to collect the pieces of the omnipotent Key to Time, The Doctor, K-9 and his new assistant Romana arrive. Collecting the first segment is not going to be easy…

Trying to obtain the first segment of the Key to Time, the Doctor and Romana are swept up in an elaborate con. The target – the homicidal Graff Vynda K.

Prisoners of the maniacal Graff Vynda K, the Doctor and Romana must break out and pursue the first segment – even as Unstoff takes it into the most dangerous place on Ribos.

Trapped in the catacombs between a mad warlord and ravenous monsters, the Doctor and Romana work desperately to obtain the segment of the Key to Time - and escape alive.

Planet Zanak, unknown time. The Doctor and Romana are seeking the planet Calufrax where the second segment waits. They are in the right place and the right time… but on the wrong planet.

The Doctor begins to investigate the mysteriously wealthy planet Zanak. Mentiads, a deranged Captain, strange omens, miraculous mines – what does it all mean? And what does it have to do with the Key to Time?

The Mentiads take the Doctor, Romana and Kimus to a reunion with K9 and Mula, where they set about trying to defeat the Captain.

The Captain and Xanxia work toward their secret goals. Both depends on the pirate planet consuming one more victim - Earth.

England, the late 1970s. The Doctor and Romana arrive in search of the third segment. But the Tracer readings are erratic and something ominous is happening with an ancient stone circle...

The quest for the Third Segment has landed the Doctor and Romana in the midst of a druidic cult centred on a stone circle. But the stones are not what they seem, and somewhere out there is a blood-thirsty Celtic goddess.

Chased by blood-thirsty stones, the Doctor must find a way to rescue Romana. What awaits him in the theoretical absurdity of hyperspace?

Facing a sentence of death from merciless justice machines, the Doctor must play for time while Romana tries to discover just who Vivian Fey really is.

Arriving on Tara, Romana locates the fourth segment of the Key to Time with ease. But getting it away proves more difficult, as she is captured by the scheming Count Grendel who wants the throne of Tara for himself.

The Doctor must employ a desperate gambit to keep the evil Grendel off the throne. And the Count has a new pawn to play - Romana.

The battle for control of Tara turns into a duel of wits between the Doctor and Grendel. But the Count shows he has more treacherous tricks up his sleeve.

Grendel plans two weddings and a funeral to cement his hold over Tara. The Doctor and K-9 race to foil him and save the Time Lady's life.

The Third Moon of Delta Magna, The Future. The Doctor and Romana arrive in search of the fifth segment and are immediately swept up in a conflict between the crew of a new refinery and the embittered natives…

The Doctor and Romana try to avoid being sacrificed to Kroll – just in time for the real monster to appear.

The massive Kroll is awake and killing anyone in its path. And the swampies are determined to appease it – by sacrificing the Doctor and Romana.

The Doctor and Romana are trapped between the monstrous Kroll and the insane refinery commander. And there is no sign of the fifth segment of the Key to Time.

Searching for the sixth segment, the Doctor and Romana land in the midst of a brutal nuclear war between the planets Atrios and Zeos.

Swept up in an apocalyptic war, the Doctor must help the Marshal defend his planet. But who or what controls the Marshal?

The Doctor meets a new enemy – the Shadow – who wants the Key to Time. And the Atrian-Zeon war is approaching an awful climax.

The Doctor is forced into a desperate gambit to prevent a massacre. But it is getting harder to tell friend from foe.

The Doctor and Romana finally venture into the Shadow's lair. The Shadow appears to hold all the cards but the Doctor has found an old friend.

The Doctor and the Shadow have their final confrontation to take control of the Key to Time. Completing it may entail an awful sacrifice. And the Black Guardian will do anything to obtain it and plunge the Universe into chaos.

The planet Argolis, around the year 2290. The Argolins live in a huge shielded city, protected from the irradiated wasteland outside. The planet's survival depends on the tourists their Leisure Hive attracts. But a series of horrific deaths seems to jeopardise that future - can the Doctor and Romana find a solution?

Another man is found dead, strangled by the Doctor's scarf, so the Doctor is put on trial. By some of the archaic rules of law, he's made to "prove" his innocence by becoming a test subject in a new tachyon experiment with time. The result will prove his innocence or guilt, so they say.

With the Doctor suffering from the time experiment, the clandestine schemes of others start coming to light, along with the secreted purposes to which the tachyonic generator has been used.

With the saboteur and murderer revealed and arrested, peace should now be restored, but a new threat emerges - a war-monger who's both ready and eager to aggress upon other worlds with a newly manufactured warrior army.

The desert planet Zolpha-Thura, the 1980s. Giant intelligent megalomaniac cactus Meglos is planning to conquer the galaxy but first it needs the dodecahedron, a powerful energy source currently on the planet Tigella. To get it back Meglos recruits a band of galactic mercenaries and hatches a cunning scheme requiring it to impersonate the Doctor...

With the TARDIS occupants trapped in a chronic histeratic loop (forever reliving the same moment in time), the devious Meglos - disguised as the Doctor - gains the trust of the Tigellans along with full and private access to their power chamber.

Can Romana escape the Gaztaks ? What has become of the Dodecahedron ? What pressing appointment awaits the Doctor ?

With the Doctor about to be ritualistically sacrificed to appease the god Ti for stealing the dodecahedron, Meglos and the pirates return to Zolfa-Thura with the dodecahedron to fire up an ancient weapon and blast Tigella out of existence.

Deep space, an unknown time - on course for Gallifrey, the TARDIS passes through a strange disruption. When they materialise, the scanner shows the Time Lord homeworld... but the travellers have passed into the negative pocket universe of E-Space and are in fact on the planet Alzarius, where evolution works very differently...

As the humanoid community takes refuge in their crashed spaceship, venomous marsh spiders begin to hatch from the local fruit while bestial marshmen emerge from the waters to walk the land. It is quite apparent that the marshmen desire entry into the spaceship. Meanwhile, as a curious marshchild shadows the Doctor, a group of teen rebels decides to take over the TARDIS.

Infection from a spider bite causes Romana's personality to change. Meanwhile the Doctor, after discovering that the spaceship society is in a perpetual state of repair and upgrade, has morality issues with the ship's leading scientist who readies himself to perform gruesome experiments on the live marshchild while it's fully conscious.

Marshmen invade the Terradonian ship thanks to Romana, who seems to be in communion with them. While the ship's inhabitants flee for their lives, the Doctor discovers a crucial fact why these humanoids can never return to the planet Terradon.

Still trapped in negative E-Space, the TARDIS lands on an unnamed world to find a society sliding back into feudalism. What is the secret of the Three Who Rule? And what ancient enemy of the Time Lords is stirring again on this world...?

The Doctor and Romana are escorted to the tower to meet the royal leaders, hoping they can find answers to why this society evolves backwards. The Doctor recognizes the tower as an old Earth spaceship, and further finds that the old fuel tanks, far from empty, are full - but with blood. Meanwhile, Councilor Aukon senses intelligence in Adric and selects him to be the their first "Chosen One."

The Doctor finds archive material in the TARDIS that tells him he's dealing with an ancient enemy of the Time Lords, a nearly indestructible king vampire who's ready to revive and reenter normal space, spreading death, once again, across the universe.

The Doctor joins the villagers' revolt against their vampire rulers, unsure how to kill the king vampire. Meanwhile Adric is first in line to join the new vampire order while Romana is laid out as a sacrificial Time Lord for the awakening king vampire and his swarm of bats.

The TARDIS is drawn into an empty white void, somewhere between universes. But they are not the only ones trapped there.

When Rorvik learns that Romana is a time sensitive, he takes her prisoner, forcing her to find a way out of the void. The Doctor attempts to discover what lies beyond the mirror.

While Biroc leads the Doctor to a view of the Tharil's lordly past, Romana learns more about the damaged freighter and the coldheartedness of its crew. Meanwhile Commander Rorvik, confounded by the time mirror inside the universal center gateway, ignores evidence that it's no simple mirror and decides to blast it, imperiling the lives of everyone.

The Doctor deduces that the freighter is a slave ship loaded up with Tharils to be sold as time machine components, but the immense weight of Rorvik's damaged ship, designed to contain the Tharils, is now collapsing the fragile void of the micro-universe in which they're all stuck, pulling everything inside ever closer.

The planet Traken. The Traken union is a society living in perfect harmony, watched over by the powerful but benign Keeper. But now the Keeper is dying, and he senses a great evil within his protectorate. Can the Doctor help him discover the secret of the Melkur?

Tremas claims consular privilege to protect the Doctor and Adric from execution, though it binds his fate to theirs if they're found guilty of murder. Melkur strengthens his hold over Kassia while Seron decides to have rapport with The Keeper to learn truth, and Adric finds evidence of another TARDIS in the area.

With Tremas falling under suspicion, due to his association with the Doctor, a new Keeper Nominate is named. Now, with everything in place, Melkur has only a short wait before his full malevolence can unfold.

With the merciless Melkur in control of The Source, the Doctor and his allies have only a slim chance of deposing him, which also puts the peace of the Traken Union in severe jeopardy.

Deciding to repair the TARDIS' chameleon circuit, the Doctor goes to Earth to find a real police box. But an old enemy is one step ahead of him.

The Doctor, aware that his time may soon be ending, travels to the Logopolis where a series of fateful events are set in motion.

With Nyssa from Traken unexpectedly rejoining the group, Adric aids the Monitor of Logopolis in trying to save the Doctor before time runs out. The Master, at liberty to prepare, is finally ready to reveal his true target, which unknowingly sets off the biggest catastrophe of all time.

With the universe collapsing, the Doctor forms an uneasy alliance with the Master to save it. In case all does not go well, the Watcher takes the Doctor's companions to a safe place, but his plans for them don't stop there. The one hope for all lies back on Earth.