A newly exiled Doctor accompanies Liz Shaw and the Brigadier to a symposium held in an imposing Scottish castle. Professor MacLeod and her son have developed a new treatment for memory loss and a possible cure for dementia.
As the Doctor investigates sightings of strange mythical creatures, and ghosts are unleashed in the castle's corridors, Liz and the Brigadier search for a connection.
Just what is happening to the energy produced by the MacLeods' revolutionary treatment? And what is the strange creature that hides in the castle grounds?
CAST: Tim Treloar (The Doctor), Daisy Ashford (Liz Shaw), Jon Culshaw (Brigadier Lethbridge Stewart), Mark Elstob (Peter Macleod / Nelophex), Susan Harrison (Dr Fiona Lynch / June Wellesley), Rosalyn Landor (Professor Abigail Macleod), Glen McCready (Professor Albert Heber / The Steward / Andrew Wellesley), Milo Ratter (Crouch). Other parts played by members of the cast.
But just what is happening to the energy produced by the MacLeods' revolutionary treatment? And what is the strange creature that hides in the castle grounds?