Story Code '6C'
by Peter Grimwade
The TARDIS finally materialises at Heathrow airport, where the Doctor is asked by officials to aid in the investigation of a missing Concorde that disappeared in flight. He stows his TARDIS aboard another Concorde, and he and his companions follow the previous aircraft's flight path. The Concorde is transported back to the Pleistocene era by a time contour, where the Doctor meets Kalid, a strange Arab magician, who controls protoplasmic creatures known as Plasmatons from his citadel with the use of psychic energy. Kalid is revealed to be the Master, who is attempting to control the Xeraphin, an alien gestalt intelligence with high mental powers, whose planet was devastated in a galactic war. The Master wants to install the Xeraphin intelligence into his TARDIS, using it as a dynamorphic generator, but his interference causes the Xeraphin to split into two facets; the Master is able to gain control of the evil side of the Xeraphin, while Nyssa is able to commune with the Xeraphin's good side. The good Xeraphin helps her and the Doctor to stop the Master's plans, and the Doctor uses the Master's TARDIS to send the Xeraphin, together with the renegade Time Lord, back to their restored home world, where the Master is to be held for his crimes against the aliens. The Doctor takes the crews from both Concordes back to the present day, and then he and Nyssa leave in the TARDIS, accidentally leaving Tegan on Earth.
Peter Davison (The Doctor), Janet Fielding (Tegan), Sarah Sutton (Nyssa), Richard Easton (Captain Stapley), Keith Drinkel (Flight Engineer Scobie), Michael Cashman (First Officer Bilton), Peter Dahlsen (Horton), Brian McDermott (Sheard), John Flint (Captain Urquhart), Peter Cellier (Andrews), Judith Byfield (Angela Clifford), Leon Ny Taiy (Kalid)*, Nigel Stock (Professor Hayter), Anthony Ainley (The Master), Matthew Waterhouse (Adric), Hugh Hayes (Anithon), André Winterton (Zarak)
Note: Pseudonym for Antony Ainley to conceal the plot twist
Produced by John Nathan-Turner
Directed by Ron Jones
Part 1 - 22nd March, 1982 @ 6.55pm - 7.20pm
Part 2 - 23rd March, 1982 @ 7.05pm - 7.30pm
Part 3 - 29th March, 1982 @ 6.55pm - 7.20pm
Part 4 - 30th March, 1982 @ 6.50pm - 7.25pm
*Featuring the Fifth Doctor, Nyssa and Tegan
*Working titles: 'Zanadin' and 'Xeraphin'