Another great and memorable monster for this story - a superb start to Pertwee's tenure. The show continues to move at wildly faster pace than ever before. It is obvious that they have decided to revamp and relaunch the show entirely, it is aimed at a new action loving audience. Jon Pertwee is undoubtedly my favourite incarnation of The Doctor so far and his energetic initial 11 episodes could not have been more of a gift for him. He looks like he is having the time of his life playing this role, I feel really invested in his portrayal.

I am loving the regular cast of UNIT, the Brigadier is a wonder, and I am comfortable with the new form of the show. Perhaps Doctor Who can be set just on Earth after all. I believe that it is because of these features that the first two stories of season seven have been able to enter a more adult and thoughtful territory. The display of workers being driven insane by mysterious circumstances and a woman dying of fright are unprecedentedly dark themes. The deaths in this season feel "more real" than before.

The concept behind the Silurians is my favourite for any monster in the show so far. The idea that they have always been inhabitants of Earth and that they are a highly developed race is really subversive and is a great starting point for this story. The writing also allows for the monsters to be seen with greater nuance - some of them are good, some of them are bad. I particularly enjoyed being able to see the world through their eyes, the "three eye camera" moment helps make them a terrifying creeping menace (and is some great direction!) The Silurian caves, with their human prisons look brilliant and give you an other worldly sense that I was worried this Earth bound season would be missing.

Where the Silurians start to become less impressive is when they are revealed and speak for long periods of time. They are unfortunately written to sound like children ("now I am the leader!") when we are told that they are a highly developed race. On top of this I feel that no effort has been put into their movement, which is clunky throughout these scenes. In terms of their costumes, the way they are realised is fine and they work well when they are not on screen for too much time but when their screen time increases mid-way through the story their long conversations with rubber mouths look terrible and do not help sell the plot. It is for this reason that Part Four is much worse than the surrounding six episodes.

My only other criticism of this otherwise excellent story is that Liz Shaw is still too stern and pensive, she just seems slightly annoyed all the time. I am delighted that the writers have decided to write an outwardly feminist character, reflecting its diverse audience - but I don't feel that they are particularly great at writing for women. Its as if they think that women who are not damsels in distress must be resistant to fun!! Perhaps its down to the fact that we are moving into an action based "James Bond" territory that her characterisation simply doesn't suit this testosterone fuelled environment. The caveat I would like to add to this is that I truly believe that Caroline John is doing very well considering the part she is given. I bet she could be great fun given the chance.

The ending of this story is excellently handled. The Brigadier destroys the Silurians underground base against The Doctor's instructions.
This pits our two favourites against each other in a dramatic twist. The Doctor's dream of a peaceful unity between the two races is destroyed. The Doctor, quite rightly is horrified at this act of genocide.