After discussing a strange pupil, Susan Foreman, teachers Ian and Barbara follow her to a junkyard. They meet her grandfather, the Doctor, and force their way inside a police box with frightening results.

The enigmatic Doctor, afraid that schoolteachers Ian Chesterton and Barbara Wright will reveal his secrets to the people of 20th century Earth, has taken them and his granddaughter Susan back to the dawn of human history. There, the four travellers are dragged into the savage politics of a tribe of cavemen who have lost the secret of making fire…

Prisoners of the earliest humans, the TARDIS crew are caught in a deadly power play for leadership of the tribe.

The TARDIS crew must make fire for the early humans to stay alive. But once they do, they may not be allowed to leave!

Time Unknown, Planet Unknown. The TARDIS lands in an eerie petrified forest overlooking a magnificent steel city. The Doctor wants to explore the city – but what is waiting there?

The dead planet is not uninhabited after all. The Doctor is about to meet what will become his greatest enemies. And he and his crew are dying of radiation sickness.

Imprisoned on Skaro by the scheming Daleks, the Doctor and his companions work to escape their clutches.

The time travellers work desperately to both escape the Dalek city and prevent a bloody massacre.

The time travellers have escaped from the Daleks, but left a vital piece of the TARDIS behind. Getting it back will mean pushing the Thals to mount a dangerous operation.

Ian, Barbara and the Thals struggle through the caves to reach the Dalek city. Will they get there in time? Is there even a way through the treacherous caves? And what are the Daleks planning?

Time is running out as the Doctor and his companions try to defeat the Daleks before they wipe out all life on Skaro.

A mysterious explosion has knocked the TARDIS into void. And in their confusion, the crew are turning on one another.

The TARDIS is adrift, the crew turning on each other. Only by working together can they find their way out before they are destroyed.

The TARDIS experiences a total power failure and is stranded in the Himalayas in the 13th century. The travellers are forced to join the caravan of the famous explorer, Marco Polo, in order to survive -- but Polo, fascinated by their claims that the TARDIS can fly through the air, seizes it on behalf of Kublai Khan in the hope that presenting the Khan with such a fabulous gift will convince him to let Polo return home to Venice. The travellers are forced to accompany Polo on his long trek across Asia to the Khan's court, but their many attempts to reclaim their property are foiled -- not just by Polo, but by the war lord Tegana, who is apparently on a mission of peace but has entirely different plans for dealing with Kublai Khan...

Tegana sabotages the party's water bags, leaving them in dire need of fresh supplies.

The Doctor and Susan are able to supply Marco with condensation that has formed inside the TARDIS, saving the group from dying of thirst. When the group are reunited with Tegana, the travellers begin to suspect he is up to something.

The Doctor's group manage to rescue Barbara from the Mongols but once more Marco remains unaware of Tegana's involvement.

The Doctor and his friends elect to warn Marco of Acomat's attack even though it means losing their chance to gain access to the TARDIS.

The Doctor, Ian and Barbara are forced to surrender to Tegana and Marco, leaving both of them the opportunity to gain possession of the TARDIS.

Tegana finally makes his move to assassinate the Khan, giving the Doctor and his friends an opportunity to thwart his plans and regain the TARDIS.

The alien world of Marinus. Perfect peace has reigned here for decades due to the mind-controlling influence of a machine known as the Conscience. But now a race known as the Voord have developed an immunity and Arbitan, keeper of the machine, has been forced to scatter the vital control keys around the planet. Now he needs the help of the time travellers to get them back - it will be an extraordinary journey, with perils every step of the way...

The Doctor and his friends arrive in the apparently idyllic city of Morphoton but Barbara soon begins to realise there is more to their hosts than meets the eye.

The search for the second key takes the travellers to a jungle where Ian and Barbara come under threat from rapidly growing plants.

Searching for the third key, Ian and Barbara meet with the sinister trapper Vasor before following Susan and the others into a cave system guarded by the mysterious Ice Soldiers.

The group are reunited with the Doctor in the city of Millennius where Ian faces trial for murder after the fourth key is stolen.

When the TARDIS malfunctions and the doors open in the time vortex, the travellers and their Ship shrink to the size of insects. When they arrive on Earth, they uncover a murderous plot involving a new insecticide - but how can they stop the crime in their miniaturised condition ? (Originally broadcast in three parts.)

Ian and Barbara are accidentally taken into Smithers' laboratory and, while the Doctor and Susan face a hazardous journey to reach them, they witness the deadly effects of DN6 first hand.

The Doctor and his friends face a race against time to expose Forrester's plans and return to normal size before Barbara succumbs to the effects of DN6.

Ian and Barbara believe the TARDIS has finally returned to their contemporary London, but soon discover signs of plague and warfare. Their old enemies, the Daleks, have invaded the Earth of the 22nd century. Separated and fighting for their lives, the travellers must try to aid the remaining humans and overthrow the Daleks' cruel tyranny. (Originally broadcast in six parts.)

The Doctor and Ian are taken to the Dalek saucer while Susan and Barbara join the rebels in planning an attack.

The Doctor manages to escape from the Dalek saucer and meet up with Susan and David but Ian is left trapped onboard. Meanwhile, Barbara and her new friends face a dangerous journey across London.

While Susan and David try to find a way out of London, Ian and Larry infiltrate the Dalek mine workings.

The Doctor's party investigate the Daleks' central control in Bedfordshire while Barbara and Jenny's attempt to reach it are derailed when they are betrayed.

The Daleks' plan to transform Earth into a giant spaceship and wipe out its inhabitants is nearing completion and the Doctor and his friends face a race against time to prevent them from destroying the planet's core.

On the planet Dido, the monstrous Koquillion terrorizes Bennett and Vicki, the only survivors of a crashed spaceship. When the TARDIS lands, the Doctor, Ian, and Barbara team up with Vicki to discover what Koquillion is hiding. (Originally broadcast in two parts.)

The Doctor and Ian reach the crashed spaceship and meet up with Barbara and Vicki, where the Doctor uncovers the truth about Koquillion.

The travellers decide to take a holiday near ancient Rome, but after a month the Doctor gets restless. He and Vicki determine to visit Rome, and while they are gone Ian and Barbara are abducted by slave traders. All roads lead to Rome, however, and the travellers find themselves at the mercy of the country's petulant emperor, Nero... (Originally broadcast in four parts.)

While the Doctor and Vicki meet with Nero, Barbara is taken to Rome to be sold while Ian is forced to work as a galley slave.

Ian and Delos are forced to fight each other for their freedom while the Doctor has to perform for Nero's court.

Ian and Delos manage to escape from Sevcheria and Tavius agrees to help Barbara rejoin them.The Doctor's attempts to avoid being thrown to the lions inadvertently result in Nero deciding to burn down Rome.

The TARDIS is drawn by a mysterious force and lands on the alien planet Vortis. There the Doctor, Ian, Barbara and Vicki find themselves caught up in a war between an evil force known as "The Animus", its ant-like Zarbi allies, and the butterfly-like Menoptra race and their allies the subterranean Optera.

The Doctor, Ian and Vicki are captured by the Zarbi while Barbara meets up with the butterfly-like Menoptera who are trying to reclaim the planet.

The Doctor is forced to co-operate with the Animus but Ian uses the opportunity to make an escape attempt.

Ian and Vrestin are captured by the subterranean Optera while Barbara and her Menoptera allies attempt to escape from the slave camp.

Barbara and the surviving Menoptera take refuge in the Temple of Light while the Doctor and Vicki attempt to escape by taking control of a Zarbi.

The Doctor and Vicki are taken before the Animus but the isoptope is left behind in the laboratory.The only hope of victory lies with Barbara and her Menoptera allies.

The TARDIS lands in the Holy Land during the Third Crusade and the crew help save Richard the Lionheart from an ambush, but Barbara is captured and brought before Saladin.

While the Doctor, Ian, and Vicki are drawn into the intrigues of King Richard's court, Barbara has to cope with an impatient Saladin and the vengeful El Akir.

Barbara allies herself with a man whose were murdered by El Akir as the Doctor and Vicki are caught up in Richard's plan to offer his sister's hand in marriage to Saladin's brother.

Ian sets out with a reluctant accomplice to rescue Barbara from El Akir's palace as the Doctor and Vicki try to evade the suspicions of the Earl of Leicester.

After an encounter with a hostile robot called a Chumblie, the Doctor and his companions are rescued by a group of female Drahvins.

With the knowledge that the planet will be destroyed in two days, the Drahvins instruct the Doctor to help them steal the Rills' ship.

The Doctor and Vicki encounter the Rills and learn the situation is more complex than they thought while Steven finds the Drahvins' hospitality ever more perilous.

The Doctor and Vicki enlist the aid of the Chumblies to rescue Steven from the Drahvins and then find a way off the planet before its destruction.

Whilst The Doctor, Steven and Vicki are traveling to their next destination. On the planet Kembel, Marc Cory, a Space Security Service agent discovers The Daleks are attending a secret meeting with their allies. Where Cory discovers the Dalek's evil plan, which sets the stage for the epic 12-part adventure "The Dalek Master Plan".

The TARDIS lands in the middle of the Trojan War, where the Doctor is mistaken for the god Zeus.

While Odysseus forces the Doctor to find a way to win the war, Steven decides to get himself taken prisoner in order to enter Troy and find Vicki and the TARDIS.

With Steven and Vicki being held prisoner by the Trojans, the Doctor's only hope of seeing them again is to suggest the idea of the Trojan Horse.

The Doctor waits inside the Trojan Horse for a chance to reach his companions but Steven's assumed identity as a Greek soldier and Vicki's growing feelings for Troilus endanger their escape.

The Doctor runs afoul of the Daleks and Special Security Agent Bret Vyon on the planet Kembel.

The Doctor infiltrates the Daleks' conference to try and discover their plans, leaving Steven, Katarina and Bret to find a way off the planet.

The Doctor and his friends escape Kembel in the Spar ship but the Daleks force them down on the planet Desperus, where they are threatened by a group of convicts.

With Katarina being held hostage, the Doctor, Steven and Bret are in danger of having to given in to Kirksen's demands, while, on Earth, Chen has them listed as traitors.

The Doctor, Steven and Sara are accidentally transported to the planet Mira where Chen sends the Daleks after them.

The Doctor, Steven and Sara escape Mira in a Dalek pursuit ship but when they find the ship is returning to Kembel, they are forced to come up with a new plan to avoid the Daleks.

The Doctor, Steven and Sara visit a Liverpool police station on Christmas Day and a Hollywood film set during the 1920s.

The Daleks realise the Doctor has given them a fake Taranium Core while, on the planet Tigus, the Doctor encounters the Meddling Monk.

The Doctor, Steven and Sara travel to Ancient Egypt, pursued by both the Daleks and the Meddling Monk.

Steven, Sara and the Monk are captured by the Daleks in order to force the Doctor to hand over the Taranium Core.

The Doctor, Steven and Sara reach Kembel where they find the Daleks have betrayed their allies and imprisoned them.

With the Daleks poised to invade the solar system, the Doctor decides his only option is to activate the Time Destructor prematurely, threatening the entire planet.

The TARDIS lands in sixteenth century Paris and Steven becomes involved with a group of Huguenots.

While trying to find the Doctor, Steven discovers a conspiracy to assassinate a man known as the Sea Beggar.

Steven has discovered the identity of the Sea Beggar, but can he warn the Huguenots in time?

Steven rejoins the Doctor and they leave Paris just ahead of the massacre, leaving Anne behind.

The Doctor discovers Polly and Ben aboard the TARDIS shortly before the ship arrives in 17th century Cornwall, where the local churchwarden gives the Doctor a cryptic message shortly before being murdered.

Pike is convinced that the Doctor knows the location of Avery's treasure while Polly and Ben try to convince the locals they were not responsible for Longfoot's murder.

Polly and Ben are placed in the custody of Blake, who reveals he also has his suspicions about the Squire, while the Doctor and Kewper are forced to team up to escape from Pike's ship.

The Doctor and his friends are at the mercy of Cherub, who is now seeking Avery's treasure for himself, while Pike prepares to attack the village.

In 1986 a new planet appears in the Solar System which turns out to be a long-lost twin of Earth's named Mondas. Its inhabitants are the Cybermen.

The Doctor's warnings are ignored and the Cybermen take over the base, hampering the crew's efforts to help Zeus IV.

With the Doctor out of action, it is up to Polly, Ben and Barclay to stop Cutler using the Z-Bomb and devastating half the world.

The Cybermen take over the base again, apparently to stop the humans using the Z-Bomb, but then the Doctor realises they intend to use it themselves to destroy Earth.

The TARDIS arrives on the Earth colony of Vulcan where the newly-regenerated Doctor assumes the identity of an Earth Examiner.

While the Doctor worries about the inert Daleks in the capsules, Lesterson makes plan to reactivate one of them.

The Doctor fails to convince the colonists of the danger posed by the Daleks and soon the other two are also reactivated.

With Polly being held prisoner by the rebels, the Doctor and Ben decide to investigate them, while Lesterson discovers the Daleks are reproducing.

The Doctor and Quinn attempt to escape in order to stop Bragen using the Daleks to take over the colony.

With Bragen having taken over, the Daleks trick the rebels into turning them loose and only the Doctor can stop them wiping out the entire colony.

The Doctor, Polly and Ben arrive in 1746, in the aftermath of the Battle of Culloden, and are captured by a group of Highlanders shortly before they themselves are captured by redcoats.

Polly and Kirsty capture Lieutenant Ffinch to try and enlist his help while the Doctor tricks Grey in order to escape.

With the Highlanders imprisoned aboard Trask's ship, the Doctor attempts to expose Grey's plan.

Ben manages to join up with the Doctor, Polly and Kirsty and together they work to free the Highlanders from Trask's ship before Grey sells them into slavery.

The TARDIS materialises on a deserted beach where the Doctor and his friends are captured by primitive warriors and taken to the fabled city of Atlantis.

While Ara tries to save Polly from being turned into a Fish Person and Ben and Jamie try to escape from the mines, the Doctor discovers the full extent of Zaroff's plans.

The Doctor and Ramo are sentenced to be sacrificed to the goddess Amdo and must escape to put a stop to Zaroff's plan.

With Zaroff's plan nearing completion, the Doctor and Ben realise the only way to save the world is to destroy Atlantis.

The TARDIS arrives on the Moon in the year 2070.When Jamie is injured, the other travellers are forced to seek the help of a moonbase afflicted with a space plague.

The Doctor and his friends attempt to convince the Moonbase crew that the Cybermen are responsible for the disappearances and find a cure for the plague.

The Cybermen take over the Moonbase and begin using the Gravitron to attack Earth but Polly, Ben and Jamie come up with a way to fight back.

The Doctor, Jamie and Victoria arrive on Telos, where an archaeological group are exploring the Tomb of the Cybermen. But are the Cybermen as dormant as they believe?

The archaeologists learn they are stranded on Telos and Klieg suggests they use the opportunity to explore the Cybermen's tombs.

The Cybermen have been revived and plan to convert the archeologists into their own kind, prompting Hopper to attempt a rescue.

Klieg attempts to do a deal with the Cybercontroller while the Doctor tries to find a way to refreeze the Cybermen permanently.

When the TARDIS materialises in the Himalayas, the Doctor decides to pay a return visit to the nearby Det-Sen monastery only to be accused of murder.

Jamie and Victoria make their way to the monastery shortly before it is attacked by the Yeti.

While the Doctor and Jamie return to the TARDIS for equipment, the control sphere Jamie brought to the monastery is reactivated.

The Yeti escapes from the monastery and Victoria and Thonmi are accused of assisting it, while the Doctor and Jamie endure a perilous journey back across the mountains.

Victoria falls under the mental influence of Padmasambhva as the Yeti attack in order to drive the monks from the area.

With the Great Intelligence on the verge of becoming corporeal, the Doctor challenges Padmasambhva to a mental battle in order to defeat it.

The Doctor, Jamie and Victoria are brought to a base which is attempting to halt the flow of the Second Ice Age.

Varga revives and takes Victoria hostage as he works to revive his crew while the Doctor and Jamie find Penley stealing medical supplies.

Jamie and Arden venture out to rescue Victoria only to find the rest of the Ice Warriors are now active.

The Doctor leaves the base to try and find Jamie and Victoria while Storr tries to do a deal with the Ice Warriors.

The Doctor and Victoria are both held prisoner by the Ice Warriors as Varga decides to take over Brittanicus.

The Doctor and Victoria attempt to force the Ice Warriors to surrender control of the ioniser before the ice flow destroys them.

After the Doctor is attacked by a group of mysterious gunmen, he discovers he is the physical double of the famous scientist Salamander.

Jamie and Victoria agree to accompany Astrid to Hungary to observe Salamander's activities.

Jamie and Victoria join Astrid into attempting to rescue Denes but Salamander becomes suspicious of them.

Fariah brings the Doctor and Kent evidence of Salamander's activities but then they come under attack from Benik.

The Doctor persuades Bruce to help him infiltrate Salamander's research centre while Salamander takes drastic action to prevent Swann finding out the truth.

The Doctor discovers the true link between Salamander and Kent while Astrid tries to convince the shelter inhabitants they have been lied to.

The TARDIS becomes trapped in space before ending up in an underground station of a mysteriously deserted London.

Jamie and Victoria are reunited with Travers before Jamie joins the soldiers in attempting to find out what has happened to the Doctor.

The Doctor and Victoria are taken back to the Goodge Street base by Colonel Lethbridge-Stewart where the Doctor becomes convinced there is a traitor in their midst.

The TARDIS arrives on the planet Dulkis where the Doctor, Zoe and Jamie decide to have a quiet holiday. Only to find the Evil Dominators and their robotic slaves, The Quarks have arrived on a radioactive island, where they plan to detonate a bomb in the planet's core, which will turn the entire planet as source of radioactive fuel for their invasion fleet.

The Doctor and Jamie are captured by the Dominators, who subject them to an intelligence test, while Zoe and Cully attempt to convince the Dulcian council of the threat.

Zoe and Cully are captured by the Dominators and put to work alongside the survey team while the Doctor and Jamie decide to return to the island to help.

The Doctor and Zoe are interrogated by Rago, who is planning to present his terms to the Dulcian council, while Jamie and Cully try to find a way to strike back against the Quarks.

Jamie and Cully manage to rescue the Doctor's party and together they try to find a way to stop the Dominators before they destroy the entire planet.

The TARDIS arrives in a white void, having made an emergency take-off to escape the volcanic eruption on Dulkis. The Doctor, Jamie and Zoe find themselves in the Land of Fiction, where characters from the imagination come to life, and The Master, the mysterious ruler, chooses the Doctor to take his place.

With the TARDIS destroyed, the Doctor, Jamie and Zoe find themselves in a strange forest patrolled by mysterious soldiers.

The Doctor realises that the travellers are trapped in a world where fiction is real and where creatures are a threat if people believe in them.

The Doctor, Jamie and Zoe reach the citadel at the centre of the land, where they finally encounter the Master of the Land of Fiction.

With Jamie and Zoe having been turned into fiction, the Doctor must find a way to save them without suffering the same fate or becoming part of the Master Brain.

The Doctor and the newly formed UNIT must stop a Cybermen Invasion and a Sinister Industrialist in league with them

The Doctor and Jamie are taken prisoner by their mysterious observers and have a reunion with an old friend while Zoe and Isobel carry out their own investigation of IE.

The Doctor and Jamie return to the IE factory in search of Zoe and Isobel, where they meet with Professor Watkins and fall foul of Vaughn.

The Doctor and Jamie enlist the help of UNIT to rescue Zoe and Isobel before trying to find out what Vaughn is really up to.

The Doctor and Jamie tell the Brigadier about the Cybermen but with Rutledge under Vaughn's control he is powerless to act.

Captain Turner manages to rescue Jamie and the others, while the Doctor begins working on a way to protect everyone from the Cybermen's hypno-sound signal.

With the entire world unconscious apart from the Doctor and his friends, the Cybermen are poised to invade and only Zoe, the Brigadier and a missile crew can stop them.

The Cybermen have launched their deadly megatron bomb which will destroy all life on Earth unless the Doctor can deactivate the homing signal.

When the TARDIS arrives on the planet of the Gonds, the Doctor, Jamie and Zoe discover a world ruled and enslaved by the Krotons. The brightest Gonds are always chosen to serve as companions of the Krotons and are never seen again...

Zoe is selected as a companion for the Krotons and the Doctor insists on joining her.

Jamie is held prisoner by the Krotons who intend to recapture the Doctor and Zoe for their mental energy.

Selris succeeds in drawing the Krotons out of the Dynatrope but Eelek agrees to hand the Doctor and Zoe over to them in return for their leaving the planet.

21st century Earth is entirely dependent on the T-Mat transport system but the control centre on the moon has stopped functioning. Meanwhile, the Doctor, Jamie and Zoe meet the one man who can solve the crisis.

Eldred agrees to supply a rocket for travel to the moon and the Doctor, Jamie and Zoe volunteer to crew it.

The Doctor, Jamie and Zoe make it to the moon and join forces with Phipps but the Ice Warriors have gained control of T-mat.

As the newly-regenerated Doctor arrives on Earth, so does the Nestene too.

UNIT's attempts to locate the meteorites are hampered by the mysterious plastic Autons, being constructed by Channing at a nearby factory, while the Doctor makes another attempt to escape from the hospital.

Ransome manages to escape from the plastics factory and alert UNIT, prompting the Doctor and the Brigadier to start an investigation.

With UNIT's investigation being blocked by the Replica of Scobie, the Doctor and Liz visit Madame Tussaud's to try and find out more as Channing prepares to activate the Autons.

The Doctor and Liz are summoned to the Wenley Moor Research Centre by the Brigadier, after several staff members suffer nervous breakdowns.

The Doctor attempts to convince people there are monsters in the caves, prompting Major Baker to start shooting at a reptile man.

The Silurians contact Quinn for help in retrieving the creature while the Doctor and the Brigadier organise a search of the moors.

With Quinn dead, the Brigadier decides to take an armed party into the caves, prompting the Doctor to contact the Silurians himself.

Worried about the Old Silurian's growing friendship with the Doctor, the Young Silurian has the scientist infect Baker with a virus and then release him.

While the Doctor and Liz try to find a cure to the virus spread by Baker, the Young Silurian kills the Old Silurian and takes control of his people.

While Liz distributes the cure to the virus, the Doctor discovers the Silurians now plan to wipe out humanity by destroying the Van Allen Belt.

While the Brigadier investigates a loss of contact with Mars Probe 7, the Doctor realises signals coming from the probe are of extra-terrestrial origin.

UNIT retrieve the returned Recovery 7 but then Carrington hijacks it while the Doctor and Liz try to decode the signal he sent.

Carrington is holding the astronauts at a secret location but when he takes the Doctor, Liz and the Brigadier there they find they have been kidnapped.

Liz has been captured by Reegan's men and the Doctor begins to suspect Taltalian is more involved than he appeared.

The Doctor decides to take Recovery 7 back into space to search for the missing astronauts but Reegan sabotages the launch.

The Doctor speaks with the alien captain and learns the astronauts sent to Earth were ambassadors. However, before he can alert the authorities he is kidnapped by Reegan.

Carrington is planning to expose the aliens on live television and call for an interplanetary war and the Brigadier must rescue the Doctor and Liz in time to stop him.

England, the near future. UNIT is providing security and scientific support for the Stahlman project, an attempt to tap the Earth's core for energy. But things are already going wrong…

Strange deaths, men changing into monsters, hot green slime pouring out of the waste pipes – but Professor Stahlman is determined to press ahead with the Inferno project no matter what the cost!

The Doctor has vanished from the Inferno project… or has he? He finds himself in the same place, but everyone has changed… and the drilling is closer to its deadly conclusion.

In a parallel England, the Doctor tries desperately to convince his captors of the immense peril they are in. But they are convinced he is a spy. And penetration zero is getting close…

The parallel Inferno has broken through the Earth's crust, unleashing terrible seismic forces and dooming the planet. The Doctor hopes to return and save his world. But the bestial primords are closing in...

The Doctor is trapped in a parallel world that is going up in flames. Can he escape in time to save Earth in his own universe?

The Doctor has escaped the catastrophic destruction of a parallel world. But can he stop Stahlman before he destroys this one?

When a Nestene Energy Unit is stolen and a radio telescope sabotaged, the Doctor is contacted by a Time Lord who tells him his old rival the Master is responsible.

Attempting to find out where Jo encountered the Master, the Doctor heads to the circus where he falls foul of Rossini.

The Doctor and the Brigadier head to Farrel's factory but the Master and the Autons have already left and are distributing plastic daffodils around the country.

The Doctor discovers the plastic daffodils are designed to fire a spray that asphyxiates people, causing havoc prior to the Nestene's arrival, but before he can alert anyone he and Jo are captured by the Master.

The Doctor and Jo head to Stangmoor Prison to investigate the Keller Machine, which drains the evil impulses from prisoners' minds, while UNIT are handling security at the first world peace conference.

The Doctor is recalled by UNIT to help investigate Cheng-Tiek's murder but is unaware that Chin-Lee is under the control of the Master.

Realising Chin-Lee has been using the power of the Keller Machine to carry out assassinations, the Doctor heads back to Stangmoor, only to find the Master has teamed up with Mailer to stage another riot.

With the Doctor and Jo being held prisoner, the Master convinces Mailer to help him steal the Thunderbolt.

The Doctor is forced to help the Master control the mind parasite while Yates finds out where the Thunderbolt has been taken only to be captured by the Master's men.

The Brigadier has recaptured Stangmoor but the Master still has control of the Thunderbolt and the Doctor must find a way to stop him and destroy the Keller Machine.

When a mysterious object lands near the Nuton power complex, UNIT investigate and encounter the Axons, a group of aliens who offer the mineral axonite, which can duplicate matter, as a gift.

The Doctor and Winser begin to analyse axonite while Chinn plots to secure its use exclusively for Britain.

The Doctor and Jo are being held prisoner by Axos while Chinn is forced to organise the worldwide distribution of axonite and the Master returns to the power complex to try and steal the TARDIS.

The Doctor and Jo escape from Axos but then the Doctor offers the Master a deal; if he helps him repair the TARDIS, they can flee Earth together.

The Time Lords take control of the TARDIS and the Doctor and Jo arrive on an Earth Colony in the 25th century, where a ruthless mining company are using a dinosaur-like creature to force the colonists to leave the planet.

The Doctor discovers an Interplanetary Mining Corporation ship has landed on the planet in order to mine its duralinium, while Norton begins causing trouble at the colony.

The Doctor makes it back to the colony and warns Ashe what Dent is up to but when Jo and Winton try to find proof they are captured.

The Doctor descends into the Primitive city to try and find Jo while the colonists receive a visit from the Adjudicator.

The Master offers to help the colonists in exchange for information on the Primitive city and forces the Doctor to act as a guide by taking Jo hostage.

The Doctor and the Master are taken into the Primitive city, where the Master hopes to find the doomsday weapon, while Dent forces the colonists to leave the planet even though their ship is likely to explode.

Earth, the near future. When an archaological dig at the village of Devil's End goes disastrously wrong, an ancient power begins to revive. Can even the Doctor withstand the power of the Daemons? And just what is the local vicar up to in his spare time?

With the Doctor frozen by the energy release from the barrow, Jo calls Yates and Benton for help, but when the Brigadier tries to join them he finds the village surrounded by a heat barrier.

The Doctor explains to his friends that the Master is trying to gain the power of the last of the Daemons, a race who influenced Earth's development, while the Master brings the rest of the village under his control.

The Master orders Bert to set a trap for the Doctor at the village while a concussed Jo makes for the cavern.

The Master decides to sacrifice Jo to Azal and when the Doctor and his friends try to intervene they come under attack from Bok.

When someone tries to assassinate diplomat Sir Reginald Styles, UNIT investigate the possibility his attacker came from the future.

Jo uses the guerrillas' time machine to travel to the 22nd century where the Controller tricks her into telling the Daleks where she's come from.

The Doctor forces the guerrillas to take him to the 22nd century where he is soon captured by the Controller.

The guerrillas infiltrate the Daleks' base to rescue the Doctor and Jo and ask them to return to their own time and alter history before the 20th century is plunged into a Third World War.

The Doctor and Jo arrive on the medieval planet Peladon, where the Doctor is mistaken for the Earth Delegate of the Galactic Federation and Jo is mistaken for a princess.

The Doctor is convinced the Ice Warriors are trying to sabotage the conference but his attempts to prove it see him accused of sacrilege.

The Doctor is sentenced to fight Grun to the death and his attempt to escape leads to an encounter with Aggedor.

Hepesh's plan has been exposed but he is still determined to prevent Peladon joining the Galactic Federation by leading a rebellion against the King.

The Doctor and Jo visit the Master at his island prison where the Doctor becomes curious about a number of ships sinking in the area.

The Doctor and Jo are trapped on the fort by a Sea Devil while the Master convinces Trenchard to help him steal some electronic components.

The Doctor is held prisoner by Trenchard while the Master attempts to contact the Sea Devils.

The Sea Devils attack the island prison and rescue the Master, prompting the Doctor to venture underwater to try and contact them.

The Doctor is taken to the Sea Devils' underwater colony where he tries to make peace with the creatures, only for the navy to attack the base.

The Sea Devils take over the naval base and the Doctor is forced to help the Master find a way to revive their colony.

The Doctor and Jo arrive on the planet Solos, on a assignment by the Time Lords, where they learn that the native Solonians are mutating into ant-like mutant creatures...

Ky transports himself and Jo down to Solos and the Marshal only agrees to help her if the Doctor assists Professor Jaeger in altering Solos' atmosphere.

The Doctor and Varan travel down to Solos to search for Jo and Ky but the Marshal orders his men to pursue them.

The Doctor and his friends are led to safety by Professor Sondergaard, who tries to help the Doctor translate the tablets.

The Marshal's premature use of Jaeger's experiment is threatening to destroy Solos' atmosphere and the Doctor returns to Skybase to try and correct the damage.

The Doctor is forced to help the Marshal cover up his actions with the Investigator but Jo and the others attempt to escape to expose him.

UNIT are invited to observe a demonstration of the new TOMTIT machine, unaware its creator, Professor Thascales, is actually the Master.

The Doctor realises the Master is trying to harness the power of Kronos, last of the Chronovores, but is unaware Percival is harbouring him at the institute.

The Master enlists the help of Krasis to control Kronos while Yates tries to bring the TARDIS to the institute only to come under attack from dangers from the past.

The Master prepares to travel back to Atlantis but the Doctor links his TARDIS to the Master's to try and stop him.

Both TARDISes reach Atlantis, where the Doctor befriends King Dalios while the Master enlists the help of Queen Galleia to try and obtain the crystal of Kronos.

England, the near future. A strange anti-matter creature arrives on Earth and attacks UNIT HQ. It seems to be specifically seeking the Doctor out - but why? With the Time Lords themselves unable to help, it seems the only person who can help the Doctor is himself - or selves...

The third Doctor and Jo find themselves on an artificial world inside the black hole while the second Doctor tries to find a way to control the organism.

The Time Lord Omega reveals himself to the third Doctor along with plans for vengeance against his own kind.

Omega reveals the purpose behind bringing the Doctor to his antimatter world, but the Doctor(s) discover a startling fact about Omega that he didn't know himself and eventually strike a bargain.

The Doctor attempts to test his new dematerialisation circuit by taking Jo to Metebelis Three but instead the TARDIS arrives in the hold of a 1920s cargo ship.

The Doctor and Jo attempt to find a way out of the Scope but, when Vorg attempts to entertain the Minorans, the crew of the Bernice suddenly become a lot more dangerous.

The Doctor and Jo return to the Bernice to try and aid their escape but find themselves pursued by the Drashigs.

The Doctor escapes from the Scope and joins forces with Vorg to try and save its inhabitants but Kalik is still determined to use the Drashigs to start a rebellion.

The Doctor and Jo land on a spaceship in the far future as it is attacked by Ogrons, which the human crew see as Draconians. The Doctor and Jo are taken to Earth as spies.

The Doctor and Jo are taken to Earth, where both humans and Draconians believe them to be a spy for the other side.

The Doctor is sentenced to life imprisonment at a lunar penal colony while Jo encounters an old enemy.

The Master rescues the Doctor from the lunar penal colony, aiming to take him and Jo to the Ogrons' planet, and the Doctor's attempt to escape leaves him stranded in space.

The Doctor, Jo and the Master are taken to Draconia, where the Doctor tries to convince the Draconians of the truth.

The Doctor, Williams and the Draconian Prince head to the Ogrons' planet to find evidence of the Master's actions but the Master tricks Jo into leading them into a trap.

The planet Spiridon, the year 2540. The Doctor and Jo arrive on the trail of the Daleks, and find unexpected allies in the shape of a Thal suicide squad. But what has brought the Daleks here in the first place?

The Doctor is captured by the Daleks, while Jo is rescued by a friendly Spridon named Wester.

The Doctor and Codal escape from their cell and meet up with the Thal commandos who are trying to get into the Dalek base.

The Doctor and his friends escape from the Dalek base, prompting the Daleks to devise a plan to wipe them out.

The Doctor and his friends ambush two Daleks as part of their plan to get back into the city, but the Daleks are on the verge of unleashing their virus.

The Doctor and his friends prepare to refreeze the Dalek army but the Dalek Supreme has arrived on the planet determined to destroy them all.

While the Doctor plans a holiday to Metebelis Three, Jo and the Brigadier are intrigued by a mysterious death at a coal mine in Llanfairfach, which is being blamed on local company Global Chemicals.

The Doctor and the Brigadier attempt to rescue Jo and Bert from the mine but Global Chemicals prove distinctly uncooperative.

The Doctor and Jo manage to escape from the mine with a maggot egg but Stevens is determined to stop them analysing it.

The Brigadier calls in a full UNIT force to deal with the giant maggots while the Doctor infiltrates Global Chemicals to find out what is really going on.

The Doctor manages to escape from BOSS with help from Yates and discovers Cliff has been infected by a giant maggot.

England, the 12th century. Robber baron Irongron is recruited by Linx, a Sontaran warrior whose starship has been forced down on Earth. Linx is forced to use a time-travel device to steal resources and scientists from the future to repair his ship, but in doing so involves UNIT and the Doctor...

The Doctor tracks the missing scientists to Irongron's castle, where Linx is using them to repair his spaceship and construct advanced weapons for Irongron.

The Doctor escapes the castle with Sarah and Hal and must persuade Sir Edward to trust him before Irongron launches an attack on them.

The Doctor attempts to return the scientists to their own time, before Linx tries to use his spaceship and destroys the entire castle.

The Doctor and Sarah return to London in the present day only to find the city strangely deserted, while nearby UNIT are dealing with a series of monster appearances.

The Doctor attempts to solve the mystery of the monster invasion. His first move - the capture of a dinosaur.

Yates sabotages the Doctor's equipment to stop him finding the location of Whitaker's base but then the tyrannosaur escapes, placing Sarah in danger.

Sarah attempts to find a way off the spaceship while the Doctor tries to track down the source of the time displacements.

The Doctor has been framed as the monster maker by Finch and is on the run from the army, while Sarah attempts to alert UNIT to what Grover is up to.