The Chaos Pool (audio story)

 was the one hundred and nineteenth story in Big Finish's monthly range. It was written by Peter Anghelides and featured Peter Davison as the Fifth Doctor, Ciara Janson as Amy and Lalla Ward as Romana II.

The story is notable for several reasons surrounding guest star, Lalla Ward. This is the only piece of performed Doctor Who where she appears as both Romana II and Astra of Atrios. And, as of May 2018, it's also the only time Romana II has an audio encounter with the Fifth Doctor.

Publisher's summary
The ageless leader of a dying race believes that salvation lies within The Chaos Pool, a place that even the Guardians of Time have been unable to locate. Meanwhile Commander Hectocot and his Teuthoidian followers move in for the kill - again and again and again...

Two different races from opposite ends of time — so how can they co-exist?

In their search for the final segment of the Key to Time, the Fifth Doctor and Amy become caught in the crossfire. As the end of everything approaches, old friends and enemies reveal themselves and the final battle between the forces of Chaos and Order ignites...

Plot
to be added

Cast

 * The Doctor - Peter Davison
 * Amy - Ciara Janson
 * The Black Guardian - David Troughton
 * The White Guardian - Jason Watkins
 * Zara - Laura Doddington
 * Astra of Atrios / Romana - Lalla Ward
 * Captain Pargrave - Ben Jones
 * Commander Hectocot - Toby Longworth
 * The Voice - Cate Hamer
 * Maddenjot - Will Barton

Individuals

 * The Doctor's latest news of Romana was that she was working for the High Council.
 * Romana has previously visited Mars.

Continuity

 * Romana asks the Doctor if he was "expecting someone else." (TV: The Caves of Androzani)
 * Zara refers to the planet Erratoon and the first segment of the Key to Time. During her visit to Erratoon, she was captured and imprisoned with the Seventh Doctor's companion Ace. She also briefly met the Seventh Doctor on that occasion but did not realise his identity. (AUDIO: The Prisoner's Dilemma)
 * The Grace's banishment of the Guardians echoes the White Guardian's banishment of the Eternals. (TV: Enlightenment)
 * The stories of Amy and Zara continue in AUDIO: Graceless.
 * Romana tells the Doctor he can't see the storm that's coming. He'd later hear rumours of a great storm coming to the galaxy. (PROSE: Millennial Rites)