11 Times Doctor Who Reinvented Itself

More than any other story in the original run of Doctor Who, the opening of season seven--Spearhead from Space--represented something completely new for the program. A new Doctor, played by Jon Pertwee, made his debut in this story (having not even had a cameo at the end of the previous adventure), with an entirely new status quo.

His old companions gone, the Doctor was now trapped on earth--exiled by his own people--where he found a home with UNIT (the anti-invasion military branch who had made a guest appearance the previous year). He had a new assistant in Liz Shaw and was on his way to developing a new supporting cast to go with his new life.

More than that, the show was returning after a much longer gap off the air then there had been before (more than six months, rather than just over the summer). Further, the series had greatly reduced it's episode count (25 episodes for season seven, as opposed to 44 for season six). Finally, for the first time, the series was in color, which combined with its earth-based setting gave the story a completely different feel.