A strange signal from Earth draws the TARDIS to the island of Lanzarote, where Turlough rescues a young American girl, Peri, from drowning. Among her possessions is an artefact bearing an alien symbol - the same triangular mark that Turlough has branded into his arm. The mystery deepens when Kamelion falls under the control of a powerful mind, and the TARDIS travels to the volcanic world of Sarn. As Turlough is forced to face his past, the Fifth Doctor must stop his oldest enemy from harnessing the revitalising powers of Numismaton gas...
Directed by Fiona Cumming
Peter Davison
The Doctor
Mark Strickson
Turlough
Nicola Bryant
Peri Brown
Anthony Ainley
The Master
Peter Wyngarde
Timanov
James Bate
Amyand
Dallas Adams
Professor Howard Foster
Jonathan Caplan
Roskal
