Bizarrely, this serial follows on from the 2012 Christmas special, the future incarnation of the Doctor having given the past incarnation of the Great Intelligence the idea to come to London and conquer the Underground system with his army of yeti robots. Yes, this really happens.
It seems to start as a disaster episode: London is evacuated! Corpses in the streets! But actually the crisis is confined to the tunnels and rooms of the Underground system, so the story doesn’t swell out into a bloated epic. The core characters (mostly army personnel, although the scientist from the previous yeti story is back as an old man) have their own unique personalities and quirks, and the story stays pretty tight, much to its advantage. The timid Evans always looking out for himself provides some light relief. We don’t discover who is helping the Intelligence (unwillingly) until the end, so there’s a bit of mystery and guessing too.
Also, a lot of web. I don’t know whether the title of the serial is related purely to this or also the web-like nature of the London Underground, but a core danger throughout the story is the yeti’s web-like fungus guns (yes, this also really happens) filling up the tunnels and trapping the people in.
The yeti themselves have had a slight design change since last time (on the outside, anyway – they still have the shiny control spheres inside them and make the same noise), with browner fur and scary glowing eyes. Clearly much of the footage of them advancing through the dark tunnels was considered too scary for the overseas censors, hence much of these retrieved shots have survived the BBC’s deletion! Additionally, one completed episode exists. The other five are reconstructions. That said, they’re done well (I watched Loose Cannon’s versions, they tend to do the best work on these).
The Great Intelligence is thwarted by the Doctor’s technical skill in reverse-engineering its equipment, however it manages to escape in non-corporeal form once again… so maybe it’ll come back for a future episode. Presumably, the people of London are brought back in once the crisis is over and nobody ever mentions it again!
On the whole, I enjoyed this. The setting was unique, the evil was scary, and the Doctor was a genius. I wouldn’t rank it as a favourite but it was certainly entertaining. Just a shame so many episodes are missing in action.