As Third Doctor Jon Pertwee was so fond of saying, there's nothing more scary than coming home and finding a Yeti on your loo in Tooting Bec.
Whilst the toiletry habits of the furry robots aren't well documented, they did at least have a bash at invading London in the 1960s.
Story editor Peter Bryant was so delighted with Mervyn Haisman and Henry Lincoln's first script, The Abominable Snowmen, that he commissioned a sequel before their first episode had even aired.
The Yeti creatures themselves underwent quite a makeover. The costumes from The Abominable Snowmen were already falling apart, and had been considered by many to be a little too cuddly to send children scurrying behind the sofa. The new models were rougher around the edges and featured large glowing eyes.
The previously silent creatures also gained a voice - a roar created by the slowed-down sound of a toilet flushing. Oh dear, we're back to loos again…
The Doctor Who production team had hoped that London Transport would grant them permission to shoot the story in the London Underground. Unfortunately, the charge of £200 per hour and an agreement only to film between between 2am and 5am forced their decision to shoot much of the story in studio.
The sets were so realistic, however, that London Transport wrote a strong letter to the BBC, demanding to know how the film crew had sneaked down the tube without authorisation.
Director Douglas Camfield had previously helmed the twelve-part epic The Daleks' Master Plan, and looked to the cast of that story when seeking an actor to play the part of Captain Knight.
Nicholas Courtney, who had played Space Security agent Bret Vyon in the Dalek story was initially considered for the role of Knight before ultimately landing the role of Colonel Lethbridge-Stewart. In his next story, Lethbridge-Stewart got promoted to Brigadier. The rest is history…
A specially recorded trailer was screened at the end of previous story, The Enemy of The World. It featured the Doctor sitting in the Underground sets and reassuring younger viewers about The Web of Fear's potentially scary content:
'Thank goodness… Oh, it's you... I thought for one moment it was... I'll just sit down for a minute. I'm glad I met you as a matter of fact; there's something I want to tell you.
'When we start out on our next adventure – Jamie, Victoria and I – we meet some old friends. Yes, and we also meet some old enemies. Very old enemies. The Yeti as a matter of fact. Only this time they're just a little bit more frightening than last time. So I'll warn you that if your Mummy or Daddy are scared you just get them to hold your hand.
[sound of gunfire]
'Here we go again. I've got to go. See you soon – I hope!'
Only a film print of episode one exists in the BBC archives, although off-air audio recordings exist for all six episodes. These were used as the basis for the BBC Radio Collection's CD release of the story, featuring linking narration by Frazer Hines.