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Professor Bernice Summerfield and the Poison Seas, or simply The Poison Seas, 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...


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  • The term "Earth Reptiles" used for both Silurians and Sea Devils was established (in-universe) as a "politically correct" term in several of the Virgin New Adventures novels.
  • This audio drama was recorded on 28 June 2003.
  • This story was originally released on CD. A download version is now available.
  • This story featured the first use of the Sea Devils in an audio drama.


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