Season 13
It was during this season that the Doctor cut ties to UNIT (after Terror of the Zygons, the Brigadier would not appear again until Mawdryn Undead in 1983, and The Seeds of Doom marked the last occasion to date that the Doctor was explicitly said to be working for UNIT - as opposed to working with them as occasions warranted). Several of the serials in this season, particularly Pyramids of Mars and The Brain of Morbius, are among the best-known of the 1970s-era storylines. Though it was aired as a part of Season 13, Terror of the Zygons was actually filmed as part of the previous season; this holdover allowed the series to switch back to an autumn season start.
All Episodes
S13 E1: Terror of the Zygons (1)
S13 E2: Terror of the Zygons (2)
S13 E3: Terror of the Zygons (3)
S13 E4: Terror of the Zygons (4)
S13 E5: Planet of Evil (1)
S13 E6: Planet of Evil (2)
S13 E7: Planet of Evil (3)
S13 E8: Planet of Evil (4)
S13 E9: Pyramids of Mars (1)
S13 E10: Pyramids of Mars (2)
S13 E11: Pyramids of Mars (3)
S13 E12: Pyramids of Mars (4)
S13 E13: The Android Invasion (1)
S13 E14: The Android Invasion (2)
S13 E15: The Android Invasion (3)
S13 E16: The Android Invasion (4)
S13 E17: The Brain of Morbius (1)
S13 E18: The Brain of Morbius (2)
S13 E19: The Brain of Morbius (3)
S13 E20: The Brain of Morbius (4)
S13 E21: The Seeds of Doom (1)
S13 E22: The Seeds of Doom (2)
S13 E23: The Seeds of Doom (3)
S13 E24: The Seeds of Doom (4)
S13 E25: The Seeds of Doom (5)
S13 E26: The Seeds of Doom (6)