Some of Ace's friends have been transported to another planet where they are hunted by the Cheetah People.
Russian commandos try to steal an experimental computer from a World War II naval base as an ancient Viking curse nears fulfillment. With Sylvester McCoy.
The Doctor takes Ace to a house inhabited by aliens threatening to overthrow Britain; with Sylvester McCoy.
The Doctor and Ace witness a war between races from an Arthurian world; with Sylvester McCoy.
At a psychic circus, the Doctor and Ace discover mysterious forces corrupting the entertainment; with Sylvester McCoy.
The Doctor and Ace battle enemies from the past and present for control of a statue fired into space 350 years ago. With Sylvester McCoy.
The Doctor discovers murderous robot Kandy Man and his happiness patrol oppressing Terra Alpha residents. With Sylvester McCoy.
The Doctor and Ace find competing Dalek factions on a playground in 1963 London; with Sylvester McCoy.
The Doctor and Mel become unwitting accomplices to a criminal seeking monster-guarded treasure in Iceworld. With Sylvester McCoy.
A beautiful alien stalked by assassins accompanies the Doctor and Mel on a trip to 1959 Earth. With Sylvester McCoy.
The Doctor and Mel find pollution and deadly inhabitants overrunning an idyllic resort; with Sylvester McCoy.
The TARDIS crashes on a planet where the Rani and her batlike cohorts scheme to detonate an asteroid; introducing Sylvester McCoy.
The Doctor concludes his defense and wonders if friends will aid him. With Colin Baker.
The Doctor begins his defense, as he investigates deaths on a spaceship and tries to prevent its destruction; with Colin Baker.
The Doctor and Peri encounter a brain surgeon whose experiments have led to horrible mutations.
On Gallifrey the Doctor stands trial for his life on charges of interfering in galactic affairs; with Colin Baker.
The Doctor and Peri arrive on Thorus-Beta where an old enemy awaits. But why is the Doctor behaving so strangely, and has he betrayed his friends?
The Doctor finally presents his evidence - in the future with a new companion.
Davros uses an industrial takeover as a cover to produce more Daleks, financing them by selling frozen bodies as protein to the galaxy. With Colin Baker.
Borad plans to replace planet natives with mutants.
The Doctor (Colin Baker) journeys through time to save an earlier self (Patrick Troughton); they unite to stop time experiments.
The Master hopes to slow the historical development of Earth by destroying the minds of many eminent scientists.
The Rani extracts chemicals from Victorians' brains.
The Doctor inadvertently ruins a game.
The rulers of an isolated mining planet use videos to control their starving slaves; with Colin Baker.
The Doctor encounters an old enemy in London's sewers before discovering the man is in cahoots with an even more powerful adversary.
Cybermen capture the Doctor and Peri and bring them to Telos, where they plan to use the TARDIS to invade Earth. With Colin Baker.
Pluto Seven has failed to make contact since its return from deep space.
The Doctor is captured by the Cybermen; he discovers the source of the signal and learns the full extent of the Cybermen's plans; the very future of the human race is threatened, as this is no war of conquest, but total destruction.
The Doctor fixes the chameleon circuit, sort of, and runs afoul of the Cybermen who have just allied with Lytton.
The Rani extracts chemicals from human brains to prolong life on her planet; the Master is also there; with Colin Baker.
Identical twins are kidnapped by Azmayl, an elderly man who is a Time Lord from the Doctor's past.
The Doctor and Peri, imprisoned on Androzani Minor, are dying from a sticky skin poison; with Peter Davison.
The Doctor meets Professor Foster's stepdaughter, Peri, who travels with him and Turlough to Sarn as the Master arrives. With Peter Davison.
The Daleks reveal their plan to clone the Doctor and assassinate the High Council of the Time Lords.
The Doctor breaks Stein's conditioning; Davros' Daleks battle the Supreme Dalek's loyalists.
A Dalek plot traps the Doctor, Tegan and Turlough in a time corridor and forces them to Earth; with Peter Davison.
The Doctor, Tegan and Turlough are trapped by a Dalek plot.
Meteors force the TARDIS to an inhospitable planet populated by Earth colonists and insectlike creatures; with Peter Davison.
A quiet visit to Tegan's grandfather turns into a sinister game controlled by the evil Malus. With Peter Davison.
Silurians and Sea Devils provoke war between human powers to regain control of Earth; with Peter Davison.
The Doctor discovers that the Master has replaced the king with an imposter to thwart the signing of the Magna Carta.
Aliens who feed on human thoughts race in sailing ships from Earth for a prize of enlightenment; with Peter Davison.
The ship's passengers are discovered to be space lepers being transported to Terminus for radiation therapy.
Both the '77 and '83 Brigadiers exist in the same time zone, and their meeting could cause a temporal catastrophe.
The Doctor duels the mind-controlling Mara when it forces Tegan to take it to its home world of Manussa; with Peter Davison.
The high council sentences the Doctor to death when Omega steals his molecular blueprint from the matrix; with Peter Davison.
Needing parts from the TARDIS, the Master uses a Concorde jet as bait to lure the Doctor; with Peter Davison.
When the Doctor helps 25th-century paleontologists fight androids, he discovers a Cybermen plot to destroy Earth; with Peter Davison.
The Doctor stands accused of murder when an impostor dons his masquerade costume and kills a man. With Peter Davison.
The TARDIS materializes on 17th-century Earth, where the reptilian Terileptil plans to introduce bubonic plague; with Peter Davison.
Hindle plans to blow up the planet as the Doctor tries to release the Kinda tribesman from the grip of the evil Mara.
The Doctor and Todd learn of the prophecy from the old woman in the cave.
Hindle's behavior becomes increasingly deranged while expedition leader Sanders has become unusually docile.
The Doctor and his companions discover a set of elaborate wind chimes in a tropical forest and Tegan becomes entranced by the chimes' music.
The Tardis lands on a huge spaceship, captained by the leader of a race of technologically advanced reptiles intent on taking over Earth.
The Master sends the Tardis and its passengers, including the newly regenerated Doctor, on a course through time to the violent birth of the universe.
Tegan becomes a gateway for the evil Mara to escape onto the planet of the gentle, telepathic Kinda; with Peter Davison.
Tegan accidentally stumbles into the Tardis as the Doctor and Adric are preparing for a trip to the City of Logic.
The guardian of the Union of Traken asks the Doctor for help when an evil being, now a statue, speaks; with Tom Baker.
The Doctor follows the hijacked TARDIS to a mirrorlike gateway guarded by ax-wielding robots; with Tom Baker.
Imprisoned in an alternate universe, the Doctor and Romana land on a planet where science has been suppressed by a barbaric tyrant.
The Doctor and Romana encounter humans ruled by Deciders, preservers of a crashed starship, now stalked by marsh creatures; with Tom Baker.
Meglos sheds a cactus disguise and assumes the Doctor's form to steal the Dodecahedron from the planet Tigella. With Tom Baker.
A vacation at a resort for galactic travelers leads the Doctor to a rejuvenation fraud and an attempt to clone an army; with Tom Baker.
The TARDIS falls into a gravity whirlpool with a damaged ship of humans going to Skonnos as sacrifices to a god; with Tom Baker.
Leaving hyperspace, two ships collide, involving the Doctor and Romana with drug smuggling and jungle monsters; with Tom Baker.
Lady Adrasta, who rules by a monopoly on metal, throws the Doctor into a pit to be consumed by a creature. With Tom Baker.
In Paris, the Doctor and Romana discover an alien splintered in time conducting art fraud to finance his time-travel experiments. With Tom Baker.
The Doctor arrives on a desolate planet only to discover he is not the only person interested in the ruins of an ancient city.
The Doctor and Romana land in the middle of a nuclear war between twin planets, where they seek the Black Guardian's agent to take the sixth key. With Tom Baker.
Swampies capture Romana and offer her as a sacrifice to a mammoth squid-like god on the third moon of Delta Magna. With Tom Baker.
A count mistakes Romana for her android double and holds her captive on Tara, where she and the Doctor seek the fourth segment of the Key to Time. With Tom Baker.
The Doctor and Romana encounter strange monsters as they explore the connection between the stone circle and the missing Key segment.
The Time Lords' search for the second segment of the Key to Time leads them to a plundering pirate planet. With Tom Baker.
The Doctor and Romana set out to collect the six segments of the 'Key to Time.' Their first stop: Ribos, a planet where the inhabitants have reached a Middle Ages stage of development.
The Doctor returns to Gallifrey to invoke his presidential rights, but horrifies everyone by apparently turning traitor. With Tom Baker.
Survivors of a planetary explosion find the lost gene banks of their ruined civilization and its guardians ruled by the ship's computer. With Tom Baker.
On Pluto in the future, an alien-controlled Sun Company exploits captive humans through the misuse of commercial power. With Tom Baker.
When scientists experiment on a 12-million-year-old skull, an entity that feeds on life materializes and threatens to destroy Earth. With Tom Baker.
Cloned and miniaturized, the Doctor and Leela are injected into the Doctor's body to pursue the nucleus of a virus swarm. With Tom Baker.
The Doctor and Leela land near a fogbound lighthouse on the English coast as an alien stalks shipwreck survivors. With Tom Baker.
The Doctor and Leela encounter a 10-foot rat, visit an opium den and trail a Chinese illusionist to find the murderers of London women. With Tom Baker.
Shortly after the TARDIS materializes inside a distant planet's mobile sand miner, mining androids turn on their human commanders. With Tom Baker.
As primitive tribesmen hunt the Doctor, he must correct a programming error he made long ago in schizophrenic, alien computer Xoanon. With Tom Baker.
The Doctor returns to his home planet and is accused of the murder of the president of the Time Lords.
A long-laid trap awaits to be sprung on the planet Kastria.
Criminal mastermind Eldrad appears.
The fossil hand draws strength from a nuclear power station.
The living, semi-fossilized hand of an alien criminal executed centuries ago forces Sarah to take it to a nuclear reactor where it tries to regenerate. With Tom Baker.
The Doctor and Sarah face an alien genius.
An energy force compels the TARDIS to land in Renaissance Italy, where the Doctor intervenes in a cult's plan to enslave mankind. With Tom Baker.
Scientists discover two alien pods buried in antarctic permafrost; one grows into a seemingly unbeatable force bent on world domination. With Tom Baker.
Professor Solon wants the Doctor's head for the new body he is creating for the galaxy's worst criminal. With Tom Baker.
The TARDIS disappears, stranding the Doctor and Sarah on a duplicate Earth on which Kraals rehearse the final stages of their invasion plan. With Tom Baker.
Robot mummies controlled by an imprisoned Egyptian god of darkness build a rocket to destroy the Eye of Horus on Mars and release the deadly god. With Tom Baker.
An antimatter monster wipes out a geological expedition when the leader tries to bring antimatter into a parallel universe. With Tom Baker.
The Doctor connects the unexplained disappearance of North Sea oil rigs to an alien race inhabiting Loch Ness. With Tom Baker.
The Zygon warlord sheds his human guise and begins his conquest of the world.
The Doctor uncovers Zygon plans.
The Doctor, Sarah and Harry return to the ark to recover the TARDIS but find themselves in a different time with a crew incapacitated by a mysterious, deadly plague. With Tom Baker.
The Time Lords send the Doctor to Skaro during a war between Thals and Kaleds to stop the revenge of crippled, mutated scientist Davros. With Tom Baker.
The Earthlings prepare to return to their deserted planet but their plans are thwarted by the arrival of a curious Sontaran.
Giant wasp-like Wirnn attack the last survivors of Earth, cryogenically preserved inside an automated space station. With Tom Baker.
The Brigadier enlists the regenerated Doctor's help to find a giant robot reprogrammed to steal military secrets and kill. Introducing Tom Baker as the Doctor.
The Doctor becomes seriously injured while aiding human slaves on Metebelis 3 in a revolt against their spider rulers.
The Doctor uncovers the Ice Warriors' plot to subjugate Peladon by frightening miners into providing needed trisilicate. With Jon Pertwee.
To find the cure for a galactic plague, the Doctor must cooperate with his sworn enemies, the Daleks, on an alien planet. With Jon Pertwee.
An army hunts the Doctor across dinosaur-laden London as Operation Golden Age nears completion. With Jon Pertwee.
A Sontaran crashes in medieval England and journeys forward in time for the scientists and materials he needs to repair his ship. With Jon Pertwee.
The Doctor investigates abandoned mines full of dangerous waste products and giant mutated maggots. With Jon Pertwee.
The Doctor and the Thals try to stop the Daleks from reactivating their hibernating forces on Skaro. With Jon Pertwee.
Both sides hunt the Doctor and Jo when the TARDIS lands on Earth during a war between humans and Draconians. With Jon Pertwee.
A giant hand whisks the TARDIS, along with Jo and the Doctor, from a time loop on a 1926 Indian Ocean cargo steamer. With Jon Pertwee.
The Doctor (Jon Pertwee) and his previous incarnations (William Hartnell, Patrick Troughton) battle Omega, the first time engineer, now deranged from centuries of being trapped in a black hole.
The Master tries to seize the Crystal of Kronos and gain control of a creature with power over time; the Doctor duels with him. With Jon Pertwee.
A human officer plans to oxygenize the planet Solos and kill the natives, afflicted by a mutating plague; the Doctor intervenes. With Jon Pertwee.
The Doctor is mistaken for an ambassador to a sabotaged conference on a planet and must battle the king's champion. With Jon Pertwee.
Freedom fighters, trying to change history by traveling back in time to prevent the Daleks from conquering Earth, start a temporal paradox. With Jon Pertwee.
The Master releases a powerful alien and isolates an English village from the world while he asks the alien to make him Earth's ruler. With Jon Pertwee.
Colonists and miners feud for land rights on an alien planet; the Master schemes to rule the galaxy by controlling a Doomsday Machine. With Jon Pertwee.
The Claws of Axos are deeply embedded in the Earth's carcass. But now it seems the Doctor is only interested in saving himself...
Axos puts its plan to drain the Earth of its energy in motion even as it tries to force the Doctor to divulge the secret of time travel. And the Brigadier must turn to an unlikely ally to stop it...
The Doctor discovers an alien parasite feeding from the evil in men's minds and ultimately killing them inside a machine the Master claims cures criminals. With Jon Pertwee.
Everyday objects become lethal traps for the Doctor and companions in the Master's plot to conquer the world with the help of the Nestenes and their plastic androids. With Jon Pertwee.
The Doctor's attempt to use nuclear energy to repair the TARDIS projects him into a parallel world about to be destroyed by a duplicate project. With Jon Pertwee.
The Doctor discovers the instigator of an interplanetary war while investigating mysterious events surrounding the return of Mars-probe astronauts. With Jon Pertwee.
Reptilian Silurians wake from hibernation and try to wipe out humanity by introducing a deadly plague and raising Earth's temperatures. With Jon Pertwee.
Plastic androids replace prominent leaders following meteorite showers in England; the Doctor tries to convince the Brigadier of his identity. Introducing Jon Pertwee as the Doctor.
An engineer notes strange events.
The Doctor investigates mysterious events surrounding the return of astronauts from Mars; with Jon Pertwee.
The Time Lords aid the Doctor.
The Doctor calls for outside help.
The galaxy's fate rests with the Doctor.
The Doctor tries to thwart the aliens.
Aliens scheme to seize the galaxy.
Aliens plan to form an invincible army.
Aliens control brainwashed soldiers.
Brainwashed soldiers from the past battle.
The TARDIS lands on a warring planet.
The Doctor seizes the alien HQ and calls for the Time Lords' help to prevent the aliens from conquering the galaxy. With Patrick Troughton.
The Doctor races to save Earth.
The Doctor works against the Ice Warriors.
Ice Warriors seek control of Earth.
Ice Warriors send lethal pods to Earth.
The Doctor, Jamie and Zoe man an obsolete rocket to stop the Ice Warriors. With Patrick Troughton.
Ice Warriors send lethal Martian seed pods to Earth and manipulate the weather to promote their growth. With Patrick Troughton.
The Doctor uses acid as a weapon.
Eelek decides to destroy the Dynatropek.
Jamie takes action in the Doctor's absence.
The time-travelers land amid a revolt.
The White Robots drag Jamie and Zoe away.
A Medusa lies in wait in the maze.
A unicorn charges the travelers.
The TARDIS leaves time and space.
When the TARDIS arrives in a land of fiction, the Doctor calls on Earth champions to win a battle of wits with the computer controlling his fate. With Patrick Troughton.
The Doctor cannot stop the lava flows.
The Dominators avenge destruction of Quarks.
Toba orders Cully's and Jamie's deaths.
Quarks try to destroy the base.
The Doctor hears of invaders on Dulkis.
In the conclusion of this six-part story, It falls to the Doctor to try to foil the Great Intelligence.
The Great Intelligence continues to deploy his army of Yeti robots to take over London, and then the world. Fortunately, the villain's efforts to steal the mind of the Doctor have failed.
Col. Lethbridge-Stuart of the British Army leads a counterassault against the Yeti robots, which have taken over the London subway system.
The Doctor discovers that an army of futuristic Yeti robots has been unleashed in the London subway system.
Long after their first encounter, the Doctor, Jamie and Victoria discover that Yeti have invaded the London Underground. A very old friend lends a helping hand.
WOTAN plans to take over Earth.
The computer is called WOTAN.
The computer commandeers men.
The travelers find a thinking computer.
The Doctor meets Doc Holliday and Wyatt Earp.
Doc Holliday is the Doctor's dentist.
The Doctor searches for a dentist.
The TARDIS materializes in Tombstone on October 26, 1881, as the Doctor searches for a dentist. With William Hartnell.
The Doctor urges peace upon the travelers.
The travelers' quarrel threatens survival.
People travel via ark to a new planet.
Earth is about to be destroyed.
Daleks plot with allies to overthrow the Solar System.
The Doctor intervenes.
The time-traveler intends to alter history.
A time-traveler exists in 1066 England.
The Doctor finds a time-traveler.
The Daleks must battle the Mechanoids.
The Daleks chase the Doctor to Mechanus.
The Daleks chase the Doctor.
The Daleks chase the Doctor.
The Daleks chase the Doctor.
The Daleks build a time machine.
The Doctor tries to alter events.
The Doctor tries to alter events.
The Doctor learns he is in danger.
The TARDIS lands in the future.
The TARDIS jumps a time track to the planet Xeros into a future where the Doctor sees himself and companions exhibited in a museum of historical conquests. With William Hartnell.
Barbara intervenes in the battle.
Both Menoptera and Zarbi want Vortis.
Butterflylike Menoptera want Vortis.
The Doctor seeks the Animus.
Antlike Zarbi capture Barbara.
Barbara is captured by antlike Zarbi, under attack by the Menoptera, who hope to regain their planet. With William Hartnell.
The Doctor speaks with an invisible Animus on Vortis about an invasion by butterflylike Menoptera to regain their planet from the antlike Zarbi. With William Hartnell.
The Doctor is mistaken for a musician.
Romans think the Doctor is Nero's foe.
Slave traders capture Ian and Barbara.
When the Doctor visits ancient Rome, he is mistaken for an enemy of Nero.
The Doctor helps the two survivors.
Two people survive a spaceship crash.
The Doctor races to save Earth.
The Doctor takes action.
The Daleks plan to take over Earth.
The Daleks plan to take over Earth.
The Daleks control humans.
The tiny time travelers take action.
The time travelers are miniaturized.
The time travelers witness a murder.
The TARDIS materializes in 1963, but the time travelers are merely one inch tall, and the only witnesses to a murder. With William Hartnell.
The Doctor helps the Sensorites.
Spacemen poison the Sensorites' water.
Humans want the Sensorites' molybdenum.
The Sensorites fear human exploitation.
Telepathic beings control the spaceship.
The TARDIS lands on a 28th-century spaceship.
The Doctor and companions face danger.
Barbara is given an honored position.
Barbara is mistaken for an Aztec priest.
The TARDIS lands in a 1430s tomb.
The TARDIS lands and is captured by the guardian of an island, who forces the Doctor and his companions to find the lost keys to the Conscience of Marinus, the machine that controls the island. With William Hartnell.
The Doctor searches for lost keys.
A machine controls the island.
The Doctor seeks freedom.
The TARDIS is captured.
The TARDIS lands on a strange island.
The Doctor accuses Barbara and Ian.
An explosion blacks out the TARDIS.
Thals and Daleks battle on Skaros.
The Daleks agree to help the Thals.
Susan learns the Thals are starving.
The evil Daleks survive in metal casings.
The Thals are a race of perfect beings.
The Doctor meets Thals and Daleks.
The TARDIS lands on the planet Skaro.
The travelers escape in the TARDIS.
The travelers escape into the Forest of Fear.
The Doctor is captured for making fire.
Two London schoolteachers follow a mysterious student home to a junkyard and find the TARDIS (Time and Relative Dimensions in Space) and her crotchety grandfather. Introducing William Hartnell as the Doctor.
The Time Lords have dispatched the Doctor and Jamie to a space research station to see Dastari, the Director of Projects, about dissuading two of his scientists from further experimentations on time travel that are rattling the fabric of time.
The Doctor invokes his presidential rights on Gallifrey, then apparently turns traitor.
The Doctor collaborates with invaders; Leela, K-9 and the chancellor help the besieged Doctor.
The Doctor gets embroiled in black magic rituals and the awesome powers of the one known as Azal.
Caught in a time corridor, the TARDIS materializes on a planet where the Borad will replace the natives with mutants; with Colin Baker.
The Doctor intervenes when pacifists on Dulkis refuse to retaliate against Dominators' plans to turn their planet into a radioactive energy source. Introducing Patrick Troughton as the Doctor.
Armageddon approaches as nothing seems to stand in the way of the Shadow's dark purpose.
The Doctor and Romana arrive on the planet Atrics in the middle of a major nuclear war.
Reptilian Silurians wake from hibernation and try to wipe out humanity by introducing a deadly plague and raising Earth's temperatures.
In a 20th anniversary show, the Doctor (Peter Davison) and most of his former selves (Richard Hurndall, Patrick Troughton, Jon Pertwee and Tom Baker) are trapped in the Death Zone of Gallifrey.
The Doctor accuses Barbara and Ian of sabotage after a violent explosion blacks out the TARDIS. With William Hartnell.
A wristwatch and a gramophone on the rocky coast of England in 1066 alert the Doctor to the presence of a fellow time-traveler with plans to alter history. With William Hartnell.
The Daleks build a time machine and chase the Doctor, capturing him on the planet Mechanus, where they must battle the Mechanoids. With William Hartnell.
Bald, telepathic Sensorites control a 28th-century Earth spaceship; the Doctor discovers three deranged spacemen poisoning the Sensorites' water supply. With William Hartnell.
Barbara is mistaken for a reincarnation of an Aztec high priest and her companions given honorary positions when the TARDIS lands inside the Tomb of Yetaxa in 1430. With William Hartnell.
During a visit to Rome in AD 64, Ian and Barbara are captured by slave traders while Romans mistake the Doctor for a famous musician and foe of Nero. With William Hartnell.
The Doctor is captured by Achilles near Troy and builds the Trojan Horse while Vicki falls in love with the Trojan Prince, Troillus.
A paralyzed man and a young orphan (Maureen O'Brien) are the only survivors of a crashed spaceship. With William Hartnell.
Susan and a freedom fighter attack the Daleks' radio network while the Doctor tries other means to stop them from turning Earth into a giant spaceship. With William Hartnell.
On the planet Skaro, the Doctor becomes involved in a centuries-old war between the noble Thals and their cyborg adversaries, the Daleks. With William Hartnell.
The Doctor and friends meet warring aliens on a disintegrating planet.