This story is probably the most important story in the history of Doctor Who - the week that the fourth episode of An Unearthly Child was commissioned the series was to be cancelled after 13 episodes; after this serial the show was commissioned for a whole year; and it continues to run 60 years later. All of that is down to one thing: the Daleks.

The main thing with this serial is the introduction of the Daleks - while I personally think there are other, better Doctor Who villains they are certainly the most memorable; and a highlight when they show up. This serial shows a more sane version of the Daleks than more recent shows - while they are still genocidal maniacs they would have murdered Ian, Barbara and Susan in Episode 2 in their later characterisations. Everything else is there though; the voice, the movement; the terror that they convey. The design in this story is great across the board factoring in the budget the BBC had: just goes to show that budget isn't everything.

The core story is also great - you've got the Doctor's subterfuge to explore the city via the fluid link showing him to be a ruthless person (with that showing him up here); the saga of the radiation sickness causing a bit of initial confusion on the nature of the Daleks (although pretty clear they were the main villains); then the attack on the city with the Thals which also involved questions over pacifism vs self defence. A lot of these features would return a lot in Terry Nation's future Dalek scripts; but in their initial form here it's very good. It also is very much an indication of 60s attitudes but that is to be expected.

The main negative here is that this story is incredibly slow - this is pretty standard across all 60s Doctor Who but especially so here. I feel like this could have been a few parts shorter without losing much: especially the areas where the TARDIS crew are imprisoned, and the sixth episode in the cave. I think this is comparatively small a negative though - the wider quality of the story and the production helps to cover this up. However it knocks this story down from being a top tier story down a level.