The Web of Fear features the return of the Great Intelligence, the robot Yeti, and Professor Edward Travers (Jack Watling) from The Abominable Snowmen. More important, it features the first appearance of Brigadier Alistair Lethbridge Stewart (Nicholas Courtney). In this story, he was only a Colonel, but later, as head of UNIT, he kept popping up until well into the next century. Only the first episode of The Web of Fear survived the BBC Archive Purge, but in 2013 the rest of the episodes were discovered in Nigeria, along with The Enemy of the World, except for Episode Three, which has been reconstructed with stills and audio. The studio sets of the London Underground were so realistic that London Transport complained to the BBC that they had filmed there without permission.
Recovering from the instability at the end of the Enemy of the World, the TARDIS lands in the Covent Garden Tube Station, which is dark and deserted, as is the city outside. Professor Travers, now elderly, has inserted a control sphere into one of his Yeti robots, which escapes into London. Soon the city is covered in thick fog and a web-like fungus fills the London Underground. Travers is brought to a WWII deep shelter beneath Goodge Street Station, where his daughter Anne (Tina Packer) is trying to solve the problem, along with Captain Knight (Ralph Watson), Staff Sergeant Arnold (Jack Woolgar), and Harold Chorley (John Rollason), basically an embedded journalist.
Laying explosives at Charing Cross Station, the Military happens upon the time-travellers. The Yeti use the fungus to smother the explosion. The Doctor realizes that the TARDIS had been brought to this location by the Great Intelligence as part of its nefarious plan. The Military and the reporter are, of course, suspicious of the Doctor and believe he is a saboteur, but Professor Travers vouches for him.
Colonel Lethbridge Stewart joins the group, assuming command. Chorley, who intends to get the hell out of the place, learns about the TARDIS and goes off to find it, with the time-travellers in pursuit, but they find their way blocked by the fungus. The Yeti attack the base and leave with Professor Travers’ unconscious body. The Doctor informs the Colonel about the Great Intelligence and the TARDIS, which is their only avenue of escape. While the Colonel leads his troops over ground to Covent Garden Station, the Doctor works on a way to defeat the Yeti.
Professor Travers has been possessed by the Great Intelligence, who wants to do the same to the Doctor. The Doctor finds a way to gain control over the Yeti. Chorley has been wandering, lost, in the Underground and is hysterically frightened. After more struggles, the Doctor manages to defeat the Great Intelligence, but it escapes into space. The time-travellers return to the TARDIS.
It is hard to accept the Yeti, who looked silly enough in Tibet, running around in the Underground, though the fog and giant webs create a suitably creepy environment. The best part of the serial is Nicholas Courtney as the sceptical, humourless, unflappable, stiff-upper-lip Lethbridge-Stewart, who eventually became one of the most-loved figures in the whole Doctor Who universe. He is one of the founders of UNIT (United Nations Intelligence Taskforce, its name changed in 2008 to Unified Intelligence Taskforce because the United Nations complained), an international organization created to defend Earth from Alien threats. Lethbridge-Stewart worked with the Doctor through 23 stories, until 1989, with the Seventh Doctor. Then he appeared in the Sarah Jane Adventures and Torchwood spinoffs. Courtney died in 2011. The Brigadier’s daughter Kate (Jemma Redgrave) became the new UNIT Chief and appeared with the Eleventh and Twelfth Doctors. The Brigadier was particularly important to the Bond-like Third Doctor, who was exiled on Earth by the Time Lords for a while and worked closely with UNIT.