The Doctor tries to get everyone to Rio, but nothing quite goes as planned. They arrive in a small Welsh village where the Doctor immediately senses that the ground isn't quite right. There is a drilling rig nearby that has reached a depth of 21 kilometers when odd things begin to happen. A local village man has disappeared and soon after Amy is swallowed into the ground. The Doctor realizes that the drilling has disturbed an ancient reptilian race that has lived deep underground for thousands upon thousands of years and who are determined to protect themselves against the 'apes' who live on the surface. Written by
Did You Know?
For research, Chris Chibnall
read the original novel Doctor Who and the Cave Monsters and watched the original serial, noting the freedom writer Malcolm Hulke took with the novel in things he could not have done in the television format. See more
This is like every day to you.
Not every day. Every other day.
Doctor Who Theme
Written by Ron Grainer
Arranged by Murray Gold
Performed by BBC National Orchestra of Wales See more