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.
With the Cybermen preparing to launch a full attack, the Doctor and his friends must keep the Moonbase and the Gravitron out of their hands until help arrives from Earth.
The TARDIS arrives at a holiday camp company with the crew worried by a prediction of giant crabs and the Doctor becomes interested in the apparent madman Medok's stories of creatures that roam the colony at night.
The Doctor is unable to convince the colonists that the Macra exist and an attempt to brainwash his companions results in Ben betraying his friends.
The Doctor, Polly and Jamie are sentenced to work in the pits and an escape attempt sees Ben's loyalties called into question again.
The Doctor and Polly manage to save Jamie from the Macra and then try to show the Pilot who is really in charge of the colony.
The TARDIS materialises on the runway of Gatwick Airport, where Polly witnesses a murder only to be kidnapped before she can report it.
With Polly having apparently forgotten them, the Doctor, Ben and Jamie decide to carry out their own investigation of Chameleon Tours.
The Doctor, Jamie and Sam manage to convince Crossland to trust them and he persuades the Commandant to let them continue their investigation.
When Spencer attempts to kill them, the Doctor, Jamie and Sam become convinced Chameleon Tours are hiding something and Sam decides to book a ticket on one of their flights.
Jamie finds himself aboard the Chameleons' satellite and meets their Director while the Doctor forces the Chameleon Meadows to tell him the aliens' plans.
The Doctor and Pinto are captured by the Chameleons but the Doctor manages to use their dependence on their human originals to create dissent in their ranks.
Trying to find the stolen TARDIS, the Second Doctor and Jamie are lured into a trap by the Doctor's old enemies the Daleks.
The Doctor and Jamie investigate Waterfield's antiques shop, where they are knocked unconscious and transported back to the 19th century.
As part of the Daleks' experiment, the Doctor manipulates Jamie into attempting to rescue Victoria.
Jamie and Kemel team up to try and find Victoria, while the Doctor and the Daleks continue to monitor their progress.
With the experiment at an end, the Doctor begins to suspect the key to rescuing Jamie, Victoria and Kemel from the Daleks lies with Terrall.
The Doctor, Jamie and Waterfield follow the Daleks to Skaro, where they discover an unforeseen consequence to their experiment.
The Daleks are poised to spread the Dalek Factor throughout the history of Earth and begin by implanting the Doctor.
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.
With Travers having been captured by the Yeti, the Doctor attempts to find a way to gain control of the robots while Lethbridge-Stewart tries to recover the TARDIS.
Victoria and Travers are held prisoner by the Great Intelligence, who is planning to drain the Doctor's mind.
The Doctor and his friends are held prisoner by the Intelligence and their only hope lies with Jamie, Arnold and a reprogrammed Yeti.
The Doctor, Jamie and Victoria are taken prisoner by the staff of a gas refinery, who have lost contact with their drilling rigs and experienced mysterious drops in pressure.
Harris asks for the Doctor's help with Maggie, while Van Lutyens and the Chief Engineer attempt to find out what is blocking the impeller.
While the Doctor begins his investigation into the weed creatures, Robson is attacked by one at the refinery.
Van Lutyens' investigation of the base of the impeller places the Doctor and Jamie in danger from the Weed Creature.
With the Weed Creature poised to burst out of the pipeline and attack the base, an encounter with Oak and Quill gives the Doctor a vital clue about its weakness.
The Doctor and Jamie rescue Victoria from Robson and realise they can destroy the Weed Creature with sound waves.
The Doctor and Jamie arrive on a mysterious spacecraft whose only occupant is a dangerous Servo Robot.
The Doctor and Jamie are brought aboard the Wheel where Jamie is horrified to learn the crew plan to destroy the Silver Carrier with the TARDIS on board.
Jamie sabotages the Wheel's x-ray laser, unknowingly giving the Cybermen an opportunity to reach the Wheel.
The Cybermen instruct their human slaves to smuggle them onto the Wheel while the Doctor attempts to convince Bennett of the threat they pose.
The Cybermen gain control of more members of the Wheel crew and the Doctor realises the only way to stop them is for Jamie and Zoe to make a dangerous space walk.
Jamie and Zoe attempt to recover the time vector generator while the Cybermen realise the Doctor is on the Wheel and make him their prime target.
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.
The Ice Warriors' seed pods beginning materialising all over the globe while Slaar decides to kill the Doctor by T-matting him into space.
The Doctor and his allies manage to return to Earth via T-mat only to find the Ice Warrior has attacked the weather control station.
The Doctor manages to create a rain storm to destroy the Martian fungus before trying to find a way to stop the Ice Warriors' invasion fleet.
Space beacons are being destroyed by pirates, who are salvaging the argonite metal. When the Doctor, Jamie and Zoe arrive on one of the beacons, they are mistaken for pirates.
With the Doctor, Jamie and Zoe trapped on a beacon segment, Hermack becomes suspicious of the unruly prospector Milo Clancey.
The Doctor, Jamie and Zoe flee from the Space Corps with Clancey, who decides to seek refuge on Ta.
The Doctor, Jamie and Zoe are held prisoner by the space pirates while Caven comes up with a plan to throw suspicion onto Clancey.
Madeleine is revealed to be working with Caven, who comes up with a way to kill the Doctor and his friends whilst framing them for the piracy.
With Clancey and Issigri trapped aboard the LIZ, the Doctor, Jamie and Zoe try to convince Madeleine to help them before Caven destroys Ta.
The Doctor, Jamie and Zoe realise they have arrived in the trenches of the First World War, where the sinister General Smythe accuses them of espionage.
The Doctor and Zoe manage to escape from Ransom and attempt to rescue Jamie from the military prison.
The Doctor and his friends realise the area is divided into different time zones and decide to return to the château to obtain a map from Smythe.
The Doctor and Zoe are transported to the control centre of the war games while Jamie and Lady Jennifer fall foul of American Revolution soldiers.
The Doctor attempts to rescue Zoe and Carstairs while Jamie and Lady Jennifer try to convince the resistance of the true nature of Von Weich and the others.
The scientist examines the captured resistance fighters and realises Jamie is a new arrival on the planet while the Doctor, Zoe and Carstairs try to rescue their friends.
The Doctor, Jamie and Carstairs manage to return to the 1917 zone only to be captured by Smythe, who orders the Doctor executed.
The Doctor and the processing machine have been taken by the Aliens but the resistance are making plans to attack the control centre.
To prove his loyalty to the Aliens, the Doctor is ordered to reprocess his friends while the Security Chief finally uncovers evidence of the War Chief's treachery.
The TARDIS is drawn to the planet of the Time Lords where both the Doctor and the War Lord are placed on trial.