Professor Bernice Summerfield and the Poison Seas (audio story)

 was the third audio story of the fourth season of the Big Finish Bernice Summerfield series. It featured the Sea Devils, the first performed story to use them since the 1984 Doctor Who television story Warriors of the Deep. It was set on the planet Chosan, the setting for Big Finish's first original story, The Secret of Cassandra.

Publisher's summary
Bernice has visited the planet Chosan before, so she seems the ideal candidate to intervene when a Sea Devil colony there comes under threat from a terrorist cell. Under cover of visiting an old friend, Bernice sets out to learn who is working in league with the terrorists to ensure the eradication of the colony.

But as she delves deeper under the oceans of Chosan, she discovers that something else — something much more ancient and powerful — ­wants rid of the Sea Devils. Soon, every living thing on the planet is in peril. And all because there's no place like home...

Plot
to be added

Cast

 * Bernice Summerfield - Lisa Bowerman
 * Irving Braxiatel - Miles Richardson
 * Principal Lurnix - Ifan Huw Dafydd
 * Clinician Nedda - Nicky Goldie
 * Joanne Carver - Jenny Livsey
 * Ressix - Matt Dineen

Continuity

 * Bernice was last on Chosan approximately four years earlier in AUDIO: The Secret of Cassandra.
 * The Sea Devils were introduced in TV: The Sea Devils.
 * Bernice keeps the Time Rings which the Seventh Doctor gave to her and her ex-husband Jason Kane as a wedding present in her wardrobe. (PROSE: Happy Endings)
 * When telling her that the universe serves curve balls, she tells Nedda that she was a man once (PROSE: The Squire's Crystal) and the mother of a messiah (PROSE: The Glass Prison)