This is the episode, of course, that features the famous, iconic scene with the Cybermen marching down the steps of St. Paul's Cathedral (drink). The scene is worthy of all the accolades it receives, mostly because of the atmospheric build-up. It starts with shots of an empty street, followed by the sound of the Cyber signal gradually getting louder, then seeing several passers by on the streets affected by it. When Captain Turner bursts in and tells everyone that there are reports of hundreds of Cybermen coming out of the sewers, you believe it! Even when there's only six Cybermen on screen at one time, you believe it.
Douglas Camfield's direction and the editing really make this scene work, particularly the quick shots of the Cybermen flinging off the manhole covers, with well placed sound effects covering up the fact that the covers are made of polystyrene. I actually punched the air when I watched this scene. I've seen it almost hundreds of time on many and varied Doctor Who documentaries over the years, but when seen in context, it is one of Doctor Who's most magical moments.
Following up on Isobel and Zoe's ill advised trip down to the sewers from Episode Five, one UNIT soldier, in addition to that poor policeman from last episode, met his end at the end of a Cyberman death ray. All that Isobel offers later on to Captain Turner is a brief apology. She also does her best Polly impersonation and makes tea for everyone. Feminism in Doctor Who lasts one episode.