• Air date: 28 Dec '74 20 episodes
      The twelfth season of British science fiction television series Doctor Who began on 28 December 1974 with Tom Baker's first serial Robot, and ended with Revenge of the Cybermen on 10 May 1975. This is the first season to feature Tom Baker as the fourth incarnation of the Doctor, an alien Time Lord who travels through time and space in his TARDIS, which appears to be a British police box on the outside. He is accompanied by companions Sarah Jane Smith, continuing from season eleven, and Harry Sullivan, who joins in this season.
  • List of Episodes (20)
    • 1. Robot, Part One

      28 Dec '74
      Can the Doctor, now in his fourth incarnation. Recover from his post regenerative trauma to save the Earth from Think Tank and their plot for world domination.
    • 2. Robot, Part Two

      04 Jan '75
      The Doctor and Sarah become convinced Think Tank are behind the electronic component thefts but are unable to stop them carrying out another raid.
    • 3. Robot, Part Three

      11 Jan '75
      Sarah and Kettlewell infiltrate an SRS meeting to try and find out what Miss Winters is up to but there is a surprise in store.
    • 4. Robot, Part Four

      18 Jan '75
      UNIT attempt to get into the bunker to stop Miss Winters setting off the world's nuclear missiles but first they have to get past the K1.
    • 5. The Ark in Space, Part One

      25 Jan '75
      The Doctor's attempt to give Harry a trip in the TARDIS sees the two of them and Sarah arriving onboard a space station in the far future, with some rather deadly security mechanisms.
    • 6. The Ark in Space, Part Two

      01 Feb '75
      The Doctor and Harry revive the Ark's medtech, Vira, to help Sarah.But when station commander Noah is revived, he becomes suspicious of the newcomers.
    • 7. The Ark in Space, Part Three

      08 Feb '75
      Knowing that Noah has been infected by the Wirrn, the Doctor persuades Vira to halt the reviving of her people, knowing it will place them in danger as well.
    • 8. The Ark in Space, Part Four

      15 Feb '75
      The Doctor tries to protect the humans still in cryogenic suspension from the Wirrn, who are determined to use Earth as their new breeding ground.
    • 9. The Sontaran Experiment, Part One

      22 Feb '75
      The Doctor, Sarah and Harry teleports to Earth to ensure the planet is safe for the survivors on-board Nerva Beacon to return to Earth and re-inhabit their world. Only to find a Sontaran named Styre has captured a group of humans and conducting experiments on them to discover the human body's weaknesses, as part of the Sontaran's goal for domination of the galaxy.
    • 10. The Sontaran Experiment, Part Two

      01 Mar '75
      The Doctor learns that Styre has been experimenting on the Galsec crewmembers to pave the way for a Sontaran invasion of Earth and decides the only way to halt his plans is to challenge him to a duel.
    • 11. Genesis of the Daleks, Part One

      08 Mar '75
      The planet Skaro, the distant past. The Time Lords divert the Doctor, Sarah and Harry to this war-torn world, and give the Doctor a mission: the evil of the Daleks is about to be born here, and the Doctor is to try to ensure they evolve into less lethally aggressive beings - or, failing that, to avert their creation altogether. But has even the Doctor the right to commit genocide?
    • 12. Genesis of the Daleks, Part Two

      15 Mar '75
      The Doctor and Harry are taken to the Kaled bunker where Davros is preparing to demonstrate the Daleks, while Sarah is captured by the Thals and taken to their city as a slave worker.
    • 13. Genesis of the Daleks, Part Three

      21 Mar '75
      The Doctor and Harry head to the Kaled city to alert the authorities to Davros' plans while Sarah and Sevrin are forced to work on the completion of the Thals' rocket.
    • 14. Genesis of the Daleks, Part Four

      28 Mar '75
      The Doctor fails to prevent the Thals from destroying the Kaled city but they don't have long to enjoy their victory before the Daleks attack.
    • 15. Genesis of the Daleks, Part Five

      05 Apr '75
      The Doctor is forced to give Davros full details of future Dalek victories but opposition to Davros' plans is growing among the Kaleds and soon there is open rebellion.
    • 16. Genesis of the Daleks, Part Six

      12 Apr '75
      Gharman tries to convince the Kaleds to vote against the Dalek project but Davros has a trick up his sleeve, while the Doctor works to destroy the tape recording of Dalek victory and the Thals plan an intervention of their own.
    • 17. Revenge of the Cybermen, Part One

      19 Apr '75
      The orbit of Jupiter, the 25th century. Arriving back on the Nerva Beacon much earlier in history, the Doctor and his friends discover the satellite beset by space plague while its crew struggles to keep space traffic away from Voga, the newest moon of Jupiter. But what is the connection between Voga, the plague, and some old enemies of the Doctor?
    • 18. Revenge of the Cybermen, Part Two

      26 Apr '75
      The Doctor transmits Sarah and Harry down to Voga to cure Sarah of the Cybermat's poison but Kellman's sabotage means he is unable to bring them back.
    • 19. Revenge of the Cybermen, Part Three

      03 May '75
      The Cybermen force the Doctor, Stevenson and Lester to carry bombs to the centre of Voga while Sarah, Harry and Tyrum decide to contact Vorus.
    • 20. Revenge of the Cybermen, Part Four

      10 May '75
      The Doctor, Harry and Lester try to destroy the Cybermen's relay device, while the Vogans prepare to destroy Nerva even though Sarah is still on board.