Interstitial (audio story)

 was the two-part story comprising part of the two hundred and fifty seventh release in Big Finish's monthly range. It was written by Carl Rowans and featured Peter Davison as the Fifth Doctor, Sarah Sutton as Nyssa, Janet Fielding as Tegan and George Watkins as Marc.

Publisher's summary
When the TARDIS is drawn off-course by temporal disruption, the Doctor and his companions discover a research facility conducting dangerous experiments. But how do you fight the future when time itself is being used as a weapon?

Part one
to be added

Part two
to be added

Cast

 * The Doctor - Peter Davison
 * Nyssa - Sarah Sutton
 * Tegan Jovanka - Janet Fielding
 * Marc - George Watkins
 * Kalu - Anna-Maria Nabirye
 * Jennings - Jeremy Ang Jones

History

 * In the 30th century, paper is immensely expensive, and its use can lead to a prison sentence.
 * The Earth Centre space station Proxima was "officially active" as of 29 July 2978. It is anchored in the Centaur belt.
 * Homo habilis was "the start of mankind", the earliest example of humanity.

Science and technology

 * Marc is amazed to see a sliding door, as well as the stars from outer space through plexiglass. He also wonders what energy is.
 * Professor Kalu studies chronon science.
 * Professor Kalu and Jennings develop a chronon bomb on Proxima for Earth Central. Kalu harnesses interstitial time in its development, and creates the chronon seed.
 * The Doctor refers to chronon waves and waveforms, which carry chronon energy.
 * The Doctor explains to Marc that interstitial time theoretically exists between the beats of Planck time.
 * Chris and Kalu are both affected by time spillage in the wake of the explosion.

TARDIS

 * The state of temporal grace within the TARDIS stabilises Chris temporally.

Time Vortex

 * When he and Kalu were projected into the Time Vortex, Chris saw Titans, Vortisaurs, Chronovores, Cherubim and Warp Perceptives.

Continuity

 * Marc believes that the TARDIS is a temple, just as Katarina did. (TV: The Daleks' Master Plan)
 * The Doctor and Marc discuss encountering creatures from legend in their last adventure. (AUDIO: Tartarus) The Doctor assures Marc that the Minotaur they faced was "not [his] first Minotaur". (TV: The Mind Robber, The Time Monster, The Horns of Nimon)
 * The Doctor will encounter a chronon bomb again in his sixth incarnation. (AUDIO: Of Chaos Time The)
 * In the Time Vortex, Chris saw, among other species, Chronovores (TV: The Time Monster, PROSE: The Quantum Archangel) and Vortisaurs. (AUDIO: Storm Warning etc.)