After narrowly avoiding being caught up in web-like substance on its journey through space, the Tardis arrives in the tunnels of the London Underground railway system, only to find that the web is also in the tunnels - as is the Great Intelligence's Yeti.
Considered one of the "classic" lost stories, The Web of Fear is probably a classic because most of it is missing. There is not much need to rehash the story as it is well-known. Its virtues include solid performances from the regulars, a convincing performance by Nicholas Courtney, and some very tense scenes. Some of the problems involve the main rationale - that the whole invasion is designed merely to ensnare the Doctor. The anticipated spectacular showdown between the Doctor and the Intelligence gets scuttled mainly to give justification to a sequel. The characters of Evans and Chorley are both rather stereotypical and tiresome. In the end, there is enough good to justify its 6-part length.
I used to listen to this CD set at work all the time back in mid 2000's, thinking I'd never actually get to see these episodes. Linking narration from Frazer Hines worked well, and flowed pretty seamlessly with the audio from the episodes.