Spearhead from Space (1)

E1

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

Spearhead from Space (2)

E2

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.

Spearhead from Space (3)

E3

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

Spearhead from Space (4)

E4

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.

Doctor Who and the Silurians (1)

E5

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

Doctor Who and the Silurians (2)

E6

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

Doctor Who and the Silurians (3)

E7

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

Doctor Who and the Silurians (4)

E8

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

Doctor Who and the Silurians (5)

E9

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.

Doctor Who and the Silurians (6)

E10

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.

Doctor Who and the Silurians (7)

E11

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.

The Ambassadors of Death (1)

E12

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.

The Ambassadors of Death (2)

E13

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

The Ambassadors of Death (3)

E14

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.

The Ambassadors of Death (4)

E15

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

The Ambassadors of Death (5)

E16

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

The Ambassadors of Death (6)

E17

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.

The Ambassadors of Death (7)

E18

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.

Inferno (1)

E19

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…

Inferno (2)

E20

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!

Inferno (3)

E21

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.

Inferno (4)

E22

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…

Inferno (5)

E23

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...

Inferno (6)

E24

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?

Inferno (7)

E25

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