Last updated 24 March 2024


Episode 2

Series Episode Number: 259

World Premiere: Sat 7 Feb 1970 - 5:16pm BST [BBC One] (United Kingdom)
First Broadcast: Mon 29 Sep 2014 - 8:30pm EDT [Retro TV]
Running Time: 23 minutes 8 seconds

7.30 Million (UK)

Appreciation Index: 58 (UK)

Chart Position: 68 () (UK)

Recorded on Mon 22 Dec 1969 in Television Centre 1
Archive State: PAL Restor



Investigating the caves, the Doctor is attacked by a dinosaur-like creature. Dr Quinn is hiding a secret that could endanger the lives of everyone.


Characters hide uncredited
Doctor WhoJon Pertwee
Liz ShawCaroline John
Brigadier Lethbridge-StewartNicholas Courtney
Dr. QuinnFulton Mackay
Major BakerNorman Jones
Dr. LawrencePeter Miles
Miss DawsonThomasine Heiner
Captain HawkinsPaul Darrow
Doris SquireNancie Jackson
SquireGordon Richardson (uncredited)
SilurianPat Gorman
Silurian VoicePeter Halliday
TechnicianBarry Kennington (uncredited)
TechnicianCara Stevens (uncredited)
TechnicianJoan Harsant (uncredited)
TechnicianJohn Spradbury (uncredited)
TechnicianKeith Ashley (uncredited)
TechnicianKeith Goodman (uncredited)
TechnicianNorton Clark (uncredited)
TechnicianRonald Gough (uncredited)
TechnicianSheila Knight (uncredited)
UNIT SoldierAlan Clements (uncredited)
UNIT SoldierAlex Hood (uncredited)
UNIT SoldierAntonio de Maggio (uncredited)
UNIT SoldierBernard Barnsley (uncredited)
UNIT SoldierBryan Nolan (uncredited)
UNIT SoldierJim Delaney (uncredited)
UNIT SoldierJohn Doyle (uncredited)
UNIT SoldierMark Johnson (uncredited)