At Hall H at San Diego Comic Con on 26 July, showrunner Russell T Davies officially announced the five part Doctor Who spin-off The War Between the Land and the Sea.

Russell Tovey and Gugu Mbatha-Raw lead the cast of the new spin-off series for the BBC and Disney+, alongside fellow Doctor Who alumni and Jemma Redgrave and Alexander Devrient.

The series is created by Doctor Who showrunner and executive producer Russell T Davies, who has written the series with Pete McTighe (A Discovery of Witches, The Pact, Doctor Who).

Leading the five-part series is Russell Tovey (Feud, American Horror Story: NYC) and Gugu Mbatha-Raw (Surface, Loki, Doctor Who). The series will also see the return of UNIT alumni Jemma Redgrave (Doctor Who, Grantchester) who will reprise her role as UNIT Chief Scientific Officer Kate Lethbridge-Stewart and Alexander Devrient (Doctor Who, Ted Lasso) as Colonel Ibrahim.

Tovey, who played Midshipman Alonso Frame from the Doctor Who episodes Voyage of the Damned and The End of Time, will play a new character.

Mbatha-Raw previously played Tish Jones, companion Martha Jones’ sister in the Doctor Who television stories Smith and Jones, The Lazarus Experiment, The Sound of Drums and Last of the Time Lords. She will play an entirely different role in the spin-off.

As rumoured, the spin-off will feature Sea Devils. When the fearsome and ancient species emerges from the ocean, dramatically revealing themselves to humanity, an international crisis is triggered. With the entire population at risk, UNIT step into action as the land and sea wage war.

“I’m so lucky to work with such a magnificent cast,” Russell T Davies said. “And this is a huge, muscular, thrilling drama which will shake The Whoniverse to its foundations. When the Doctor’s not in town, the whole of humanity is in trouble.”

The War Between the Land and the Sea begins filming internationally in August 2024 directed by Dylan Holmes Williams, who filmed the 2024 Series episodes 73 Yards and Dot and Bubble.