6S. The Twin Dilemma

Season Twenty One (continued) - 1983

Script Editor: Eric Saward
Produced by: John Nathan-Turner
Writer: Anthony Steven
Director: Peter Moffat
Designer: Valerie Warrender
Incidental Music: Malcolm Clarke


The Doctor is extremely unstable after his regeneration. Peri is unsure what has happened, and when she shows a dislike of his new costume he attacks her. Peri shows him his reflection in a mirror, which has the effect of causing a small breakdown. Repentent of what he had done he chooses to go into exile with Peri. The location for the exile: a lonely moon.

The moon, however, is being used as a hideout for a group of kidnappers who have kidnapped two mathematical genius twins. The twins, with the Doctor, Peri and an investigator, are taken to the planet of Jeconda where the evil Mestor is planning to create an enormous explosion which would release sufficient energy to hatch thousands of Gastrapod eggs. Mestor has ordered the kidnapping of the twins so they can do the calculations necessary.

The Doctor manages to destroy Mestor's body, but his mind transfers to Azmael, a fellow Time Lord. Azmael, though, is on his final incarnation. He starts to regenerate, which this time causes his death, and the death of Mestor.

Regular Cast

  • Peri Brown: Nicola Bryant

Guest Cast

  • Professor Edgeworth (Azmael): Maurice Denham
  • Lt. Hugo Lang: Kevin McNally
  • Mestor: Edwin Richfield
  • Noma: Barry Stanton
  • Drak: Oliver Smith
  • Romulus Sylvest: Gavin Conrad
  • Remus Sylvest: Andrew Conrad
  • Professor Sylvest: Dennis Chinnery (1)
  • Commander Fabian: Helen Blatch (1)
  • Elena: Dione Inman (1)
  • Chamberlain: Seymour Green (3-4)
  • Prisoner: Roger Nott (3)
  • Jocondan Guard: John Wilson (3)
  • Gastropods: Ridgewell Hawkes, Steve Wickham
  • Jocondans: Mark Bassenger, Graham Cole, Les Conrad, Mike Mungarvan, David Ransley, Robert Smythe

Original broadcast on the BBC

Channel Title Date Viewers Rating
BBC 1 623. Part One Thursday, March 22, 1984 6:40 PM - 7:05 PM 7.6M 61%
BBC 1 624. Part Two Friday, March 23, 1984 6:40 PM - 7:05 PM 7.4M 66%
BBC 1 625. Part Three Thursday, March 29, 1984 6:40 PM - 7:05 PM 7.0M 59%
BBC 1 626. Part Four Friday, March 30, 1984 6:40 PM - 7:05 PM 6.3M 67%


  • Television Centre Studio 3
  • Television Centre Studio 8

Outside Locations

  • Gerrards Cross Sand and Gravel Pits, Wapseys Woof, Oxford Road, Gerrards Cross, Herts
  • Springwell Quarry, Springwell Lane, Rickmansworth, Herts


Part 1: As the Doctor and Peri prepare to go out onto the asteroid surface the Doctor hits something on the console (not the door control) and heads for the door. We hear the TARDIS door sound effect, but the door doesn't open. Which is actually for the best, because Peri says something else and the Doctor turns back for a few more lines, before going back to the console and hitting the real door control.

Part 2: The silver computer terminal in the safe-house on Titan 3 seems to be rather prone to wobbling - an obvious example being after Peri spots the bomb ticking away outside the room, and the Doctor walks away from the terminal to have a look.


The eighth title sequence, another version of the star field, is first used for this story. It is credited to Sid Sutton and Terry Handley, but all subsequent episodes credit Sutton only.