Searching for the third segment to the Key to Time brings the Doctor and Romana to present-day Earth, where the travellers have to contend with stone circles, Druidic rituals and a not-so-mythical goddess known as the Cailleach.
Tom Baker
as The Doctor
Mary Tamm
as Romana
John Leeson
as K-9 (voice)
Beatrix Lehmann
as Professor Rumford
Susan Engel
as Vivien Fay
Nicholas McArdle
as De Vries
Elaine Ives-Cameron
as Martha
