England, the near future. Mike Yates, formerly of UNIT, is disturbed by odd happenings at a monastic retreat. Using Sarah as a liaison, he is able to warn the Doctor and the Brigadier. But how is the Doctor's research into ESP and the blue Metebelius III crystal connected to Mike's warning?
Elenco:
William Hartnell
,
Patrick Troughton
,
Jon Pertwee
,
Tom Baker
,
Peter Davison
,
Colin Baker
,
Sylvester McCoy
.