BBC Announces Doctor Who Spin-Off ‘The War Between the Land and the Sea’

An ancient aquatic threat emerges from the depths to challenge humanity’s dominance over the oceans in the latest expansion of the Doctor Who universe. The five-part series centers on a reluctant diplomat thrust into a high-stakes conflict between land dwellers and the vengeful Sea Devils. Co-created by the franchise’s showrunner, the production blends intense action with environmental allegory, drawing on classic villains from the 1970s.

The narrative follows Barclay, portrayed by Russell Tovey, a former naval officer pulled from obscurity to serve as Earth’s ambassador. When the Sea Devils surface to reclaim the planet, Barclay navigates tense negotiations aboard a submerged diplomatic vessel. Led by the formidable Salt, played by Gugu Mbatha-Raw under intricate prosthetic makeup, the Sea Devils deploy guerrilla tactics, including a sequence where they transform discarded plastics into lethal weapons.

Filming occurred over 12 weeks across Welsh studios and coastal locations, utilizing practical effects for underwater sequences alongside CGI enhancements. The series features 22 speaking roles, with supporting cast including Indira Varma as a skeptical UN representative and Jack Farthing as a corporate polluter entangled in the crisis. Directors alternated episodes to maintain visual consistency, employing blue-screen technology for 40 percent of the runtime.

Russell T Davies, who co-wrote the scripts and serves as executive producer, positions the story as a direct sequel to the 1972 Doctor Who serial ‘The Sea Devils’. Davies stated, “The BBC’s never had the budget to make a proper sequel to the original Sea Devils story… It’s all about the emotion at the centre and that’s what will get you watching.” The production budget exceeded £15 million, marking the highest for a Doctor Who spin-off to date.

Tovey, known for roles in ‘Years and Years’ and ‘Looking’, prepared by undergoing free-diving training to authentic his performance. Mbatha-Raw, fresh from ‘Surface’ on Apple TV+, spent six hours daily in makeup to embody Salt’s scaled, bioluminescent form. The duo’s chemistry drives the central standoff, with improvised dialogue adding layers to the diplomatic exchanges.

The series integrates lore from the broader Whoniverse, referencing the Silurian-Earth conflicts without direct crossovers. Environmental motifs underscore the plot, highlighting ocean acidification and microplastics through the Sea Devils’ grievances. A subplot explores Barclay’s personal redemption, tied to a past maritime disaster that claimed 150 lives.

Executive producers from Bad Wolf, the studio behind ‘His Dark Materials’, oversaw post-production, incorporating Dolby Atmos sound design for immersive subaquatic effects. The score, composed by Segun Akinola, fuses orchestral swells with synthesized echoes reminiscent of the original theme.

Premiering with the first two episodes on BBC iPlayer and BBC One on Sunday, the full run concludes the following week. International rollout follows on Disney+ in early 2026, targeting 180 territories. Davies envisions potential for a second season, pending viewership metrics above 5 million consolidated viewers per episode.

Tovey praised the project’s ambition, calling it “a really beautiful, brilliant, compelling show.” Mbatha-Raw added, “It’s a wild, epic, thrilling adventure” with “so many compelling messages about the world we’re living in and what we can do about it.” The spin-off arrives amid Doctor Who’s 2025 revival push, following Ncuti Gatwa’s season finale that drew 8.2 million viewers.

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