Time itself is in peril! The Time Lords and UNIT find themselves besieged by a mythic figure from the Time Lords' past hell-bent on destruction. The only way to defeat him is to break the First Law of Time and let the Doctor help himself — literally...
Jon Pertwee
The Doctor
Patrick Troughton
The Doctor
William Hartnell
The Doctor
Katy Manning
Jo Grant
Nicholas Courtney
Brigadier Lethbridge-Stewart
John Levene
Sergeant Benton
Stephen Thorne
Omega
Rex Robinson
Doctor Tyler
