England, the late 1970s. At Fetch Priory, Dr Fendelman's experiments with the new Time Scanner are disrupted by the mysterious death nearby of a hiker. Then there's the mysterious skull, also being used as part of his work--a skull that seems to predate the evolution of mankind. What is the true role of the Fendahl in humanity's evolution?
Elenco: William Hartnell , Patrick Troughton , Jon Pertwee , Tom Baker , Peter Davison , Colin Baker , Sylvester McCoy .