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.

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?

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.

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.

The Doctor enters the labyrinth to try and protect Jo from the minotaur but the Master has seized control of Atlantis and prepares to summon Kronos again.