The suspense. The music is quiet, eerie and gets the viewer in the right frame of mind for the show ahead. There is a small base of scientists in 2070 controlling Earth weather - and an infection picking off staff one by one. Yes, another base under siege - and I love it. They aren't sent a relief rocket as hoped and left to fend for themselves against this mystery illness. The Doctor has a challenge on his hands - which becomes far more considerable when we realise that the Cybermen are back, and are in control.

The use of the Cyberman’s shadows is frightening and very effective. They are strong and fierce, impossible to reason with and feel like a genuine threat.

Kit Pedler clearly knows our four main characters inside out. Though I was gobsmacked that Polly was once again reduced to making tea for everyone.

I loved the little strand about Jamie's "Phantom Piper" and Polly and The Doctor's varying reactions to it. I was delighted to see Polly discovering a way to defeat the Cybermen using the scientific tools at her disposal. Even more delighted when she headed out with Jamie and Ben to defeat the Cybermen.

It was nice to see a grittier side to the 2nd Doctor in this story, following the silliness of The Underwater Menace.