46. The Invasion

The Invasion is one of those pinnacle moments in Doctor Who history that essentially changes the fabric of the show forever. Almost as important as the Doctor regenerating for the first time in the Tenth Planet, the Invasion sets up the series for Jon Pertwee's entire run as the 3rd Doctor. Despite the viewing audience not knowing it at the time, they were seeing a view of the future of the show.

The Cybermen make their 4th and final appearance of the Troughton era and they get another fabulous makeover. This would turn out to be the Cybermen's last proper appearance on Doctor Who until 1975, when they return in Tom Baker's 4th Doctor episode Revenge of the Cybermen. In this story, the Cybermen invade Earth, again, and strike terror in the heart of London. Popping out of sewers, running around the Underground, parading in front of St.Paul Cathedral; this is full frontal Cybermen.

To recap, the first time we meet the Cybermen, they're invading the South Pole. The second time, they're invading the Moon. The third time, we invade their tombs on Telos (our bad). The fourth time, they invade an earth space station. And now they're invading modern day London. Good times.

The story sees the return of Nicholas Courtney as Lethridge-Stewart from The Web of Fear. Now promoted to the rank of Brigadier, which he will be forever know as, he has been placed in charge of a little group called the United Nations Intelligence Taskforce also know as UNIT. Charged with handling alien invasions, UNIT is christened in a hail of fire from the Cybermen. The story is classic and iconic, showcasing Patrick Troughton's 2nd Doctor and giving us great character drama.

So the lore of this story is that with Patrick Troughton departing the role of the Doctor at the end of the season, the producers wanted to see if a series of earth-based stories with the Doctor and UNIT working together would work. This story was conceived as a pilot episode or dummy-run for the new format. With the Brigadier, came a Captain Jimmy Turner (who's position would eventually be filled by Captain Mike Yates), and a young Corporal Benton (would would get promoted to Sergeant). With the so-called UNIT family in place, the Doctor joined as a scientific advisor and the on-screen magic happened. While Patrick Troughton's 2nd Doctor had wonderful chemistry with the Brigadier, it will be Jon Pertwee's 3rd Doctor that forever cements this relationship in our hearts and emblazons his era in the history of Doctor Who.

PS. Despite Jon Pertwee being the Brig's Doctor, Patrick Troughton is reunited with Nicholas Courtney in The Three Doctors and again in the Five Doctors. Both times, it is magic with them both sparking off each other and recapturing the chemistry of these early episodes.

PPS. This Invasion is missing two of its original 8 episodes. The BBC as an experiment commissioned these two missing episodes to be animated for the DVD release. So for the first time since 1968, we are able to watch this story in it entirety. While the animation is fairly simple, it matches the look and feel of the era and wonderfully completes this great story.

http://en.wikipedia.org/wiki/The_Invasion_(Doctor_Who)