Earth, the distant future. Beaming down from the Nerva Beacon, the Doctor and his friends discover Earth is habitable once more. Unfortunately a Sontaran officer is conducting tests on a group of human colonists to determine their ability to withstand a full-scale invasion...
Elenco:
William Hartnell
,
Patrick Troughton
,
Jon Pertwee
,
Tom Baker
,
Peter Davison
,
Colin Baker
,
Sylvester McCoy
.