8. Terror of the Zygons
General Plot: The Doctor, Sarah and Harry return to earth after the Brigadier summoned them, and they arrive in the Scottish village of Tullock. UNIT are investigating a number of unexplained attacks of North Sea oil rigs with mysterious teeth marks on the wreckage. Their investigations lead them to the shores of Loch Ness, where they discover that the legendary monster is not a myth, but it is in fact a cybernetic reptile known as the Skarasen. The Doctor finds out that it is being controlled by a race of shape-shifting creatures called Zygons, whose intent is to take over the planet after their own was destroyed by solar flares. They have already begun to infiltrate government officials, and the Doctor soon realises that his friends and allies are not always what they seem.
What makes it great: The Doctor meets the Loch Ness Monster? How could that not be utterly fantastic?! It's just so magnificent, so ridiculous and yet so Doctor Who. And Terror of the Zygons does not disappoint the Zygons act as a chilling monster which have never appeared in the show since. This is a total crime one that will be rectified by their return later in the year, but a crime nonetheless that a monster as sinister and interesting has been shelved for nearly 40 years. They are used to great effect, with a menacing and threatening plot. The idea that they can infiltrate the government using their ability to shape-shift into a replica of government officials is a scary prospect, but more terrifying is the idea that they could make copies of those closest to us, meaning that essentially the Doctor is on his own in this instance as he doesn't know who he can trust. The use of Loch Ness Monster, the Skarasen, is also done to great effect. The other wonderful standout of the episode is the rare inclusion of the Brigadier and UNIT. This is the second and final time the Brigadier is used in the Tom Baker era, and he shines throughout. This story brings to a close the UNIT era, and begins a new, darker and more Gothic period for the show. The magic of the UNIT era remains throughout the story, with humour and warmth, but with a stern edge. The Brigadier finally meets an enemy that is vulnerable to bullets, which is fitting considering how he'd spent years lamenting how the foes he's facing are immune to bullets, and here in his final episode until 1983, he finds an enemy he can shoot. The military mind of the Brigadier was in its element, but so was his heart and warmth which made the character so legendary.
Memorable Quote:The Doctor: Oil? An emergency? Ha! It's about time the people who run this planet of yours realised that to be dependent on a mineral slime just doesn't make sense.