Primeval (audio story)

 was the twenty-sixth story in Big Finish's monthly range. It was written by Lance Parkin and featured Peter Davison as the Fifth Doctor and Sarah Sutton as Nyssa.

Serving as a prequel to The Keeper of Traken, it was notable for exploring the history of Nyssa's home planet of Traken and the wider Traken Union, as well as for being novelist Lance Parkin's first audio story.

Publisher's summary
Nyssa will die at dawn, and the Doctor doesn't even know why.

To save her life, he must make a desperate journey to the only place in the universe where a cure might exist to heal her.

When even that fails, the Doctor has a choice —­ let Nyssa die, or make a deal with the devil.

After all, the road to hell is paved with good intentions...

Plot
to be added

Cast

 * The Doctor - Peter Davison
 * Nyssa - Sarah Sutton
 * Shayla - Susan Penhaligon
 * Kwundaar - Stephen Greif
 * Sabian - Ian Hallard
 * Anona - Romy Tennant
 * Janneus - Rita Davies
 * Hyrca - Mark Woolgar
 * Narthex / Captain Kabe - Billy Miller
 * Etrayk - Alistair Lock

Continuity

 * This story portrays the planet Traken three thousand years before TV: The Keeper of Traken. It also tells how the Keeper's position came to be.
 * This story reveals that Nyssa's collapse in TV: Four to Doomsday and the telepathic powers which she demonstrates in TV: Time-Flight are the results of Kwundaar's manipulations. Seeking to regain control of the Source, Kwundaar needed to use a native of Traken who had left the union. He chose Nyssa. Ultimately, it is the Doctor that Kwundaar wants to use to regain control of the Source.
 * Kwundaar knows of Traken's eventual destruction. (TV: Logopolis)
 * Nyssa refers to Adric's death. (TV: Earthshock)
 * Nyssa had previously considered asking the Doctor to take her to Traken before its destruction on numerous occasions before she actually did so. (PROSE: Empire of Death)
 * Nyssa teaches Sabian the Charleston. She had herself been taught the dance by Tegan Jovanka while attending a party at Cranleigh Hall in Oxfordshire on 11 June 1925. (TV: Black Orchid)