While investigating a vanishing Concorde at Heathrow Airport, the Doctor and his companions are thrown millions of years back in time, when a mysterious alien called Kalid is trying to control the ancient powers of the Xeraphin.
Peter DavisonThe Doctor
Sarah SuttonNyssa
Janet FieldingTegan Jovanka
Anthony AinleyThe Master / Kalid
Nigel StockProfessor Hayter
Richard EastonCaptain Stapley
Keith DrinkelFlight Engineer Scobie
Michael CashmanFirst Officer BiltonJohn FlintCaptain UrquhartJudith ByfieldAngela CliffordPeter DahlsenHortonBrian McDermottSheard
Peter CellierAndrews
Matthew WaterhouseAdricHugh HayesAnithon
