As Sea Devils rise from polluted depths demanding Earth’s repentance, UNIT races against biowarfare plots and melting poles in Russell T Davies’ pulse-pounding Whoniverse miniseries.
The War Between the Land and the Sea: Humanity’s Aquatic Reckoning
The War Between the Land and the Sea is a gripping five-part science fiction miniseries in the Doctor Who universe, pitting humanity against an ancient aquatic species known as the Homo Aqua, or Sea Devils. Created by Russell T Davies, it explores themes of environmental destruction, diplomacy, and interstellar prejudice through high-stakes global negotiations led by UNIT. Premiering on BBC One in December 2025, the series blends intense action, political intrigue, and emotional depth.
Series Overview
The story unfolds when the fearsome Homo Aqua emerge from the oceans, demanding humanity address its pollution of their domain, triggering an international crisis. UNIT, the United Nations Intelligence Taskforce, steps in to broker peace amid escalating tensions, sabotage, and biowarfare plots. Spanning five episodes directed by Dylan Holmes Williams, it features returning Whoniverse characters and new leads navigating underwater diplomacy and surface betrayals. The narrative critiques human hubris while delivering pulse-pounding submarine descents and shrieking escapes.
Filmed from August to December 2024 in Wales, Cardiff, and Spain, production involved Bad Wolf and BBC Studios, with Davies executive producing alongside Pete McTighe, Joel Collins, Julie Gardner, and Jane Tranter. It debuted with episodes 1-2 on December 7, 2025, drawing 4.31 million UK viewers, followed by strong subsequent ratings.
Main Cast
Russell Tovey stars as Barclay Pierre-Dupont, a reluctant logistics manager thrust into ambassadorship. Gugu Mbatha-Raw plays Salt, the eloquent Homo Amphibia diplomat representing her kind.
Returning Doctor Who favorites include Jemma Redgrave as UNIT commander Kate Lethbridge-Stewart, Ruth Madeley as scientific advisor Shirley Bingham, Alexander Devrient as Colonel Christofer Ibrahim, and Colin McFarlane as General Austin Pierce from Torchwood. Supporting roles feature Vincent Franklin as Prime Minister Harry Shaw, Patrick Baladi as utilities magnate Sir Keith Spears, and Francesca Corney as Sergeant Hana Chakri.
| Character | Actor | Role Highlights |
|---|---|---|
| Barclay Pierre-Dupont | Russell Tovey | Unlikely human ambassador; forms bond with Salt |
| Salt | Gugu Mbatha-Raw | Homo Aqua envoy; saves Barclay multiple times |
| Kate Lethbridge-Stewart | Jemma Redgrave | UNIT leader battling PTSD and politics |
| Shirley Bingham | Ruth Madeley | Scientific advisor analyzing Homo Aqua biology |
| General Austin Pierce | Colin McFarlane | US military liaison pushing aggressive tactics |
Plot Summary
Episode 1: “Homo Aqua” – Fishermen kill a Sea Devil off Dragonera, drawing UNIT’s attention; Barclay accidentally becomes humanity’s ambassador after Salt chooses him for his respect toward the dead creature.
Episode 2: “Plastic Apocalypse” – Negotiations falter over pollution; Homo Aqua dump ocean trash worldwide, including the Titanic, killing thousands and demanding shipping halts. Barclay agrees to a deep-sea summit.
Episode 3: “The Deep” – A UNIT sub descends to the Romanche Gap; surface leaders plot “Severance” extermination, assassinating Kate’s partner instead. A bomb detonates, killing most aboard except Barclay, saved by Salt.
Episode 4: “The Witch of the Waterfall” – Salt escapes UNIT custody amid deepfakes framing her; she and Barclay flee, sharing a kiss. Her successor Tide demands her execution, threatening rust attacks on metal infrastructure.
Episode 5: “The End of the War” – Homo Aqua accelerate ice melt; humanity’s secret virus wipes out 90% of them via Severance. They surrender to the Marianas Trench, hiding tech and warning “water will find you one day.” Salt gifts Barclay gills for an aquatic future.
Themes Explored
Environmental urgency drives the plot, with Homo Aqua’s pollution retaliation mirroring real-world climate crises like ocean plastic and melting poles. Diplomatic failures highlight prejudice, as world leaders prioritize extermination over accord. Personal arcs, like Kate’s PTSD and Barclay’s romance, humanize the global stakes, echoing Torchwood’s gritty tone.
Critics praise its performances, especially Redgrave’s, and Davies’ return to spin-off roots, comparing it favorably to past Whoniverse entries for tension and relevance.
Production Insights
Davies conceived the idea pre-Doctor Who 60th specials, collaborating with McTighe on scripts. Casting leveraged Whoniverse alumni for continuity, with Tovey and Mbatha-Raw tying back via past guest spots. The series emphasizes practical effects for aquatic scenes, filmed in controlled water tanks.
Release and Reception
BBC One aired all episodes by December 21, 2025, with Disney+ streaming globally in 2026. Viewership dipped slightly but stayed solid at 3.08 million for the finale. Positive reviews highlight its bold eco-message and character-driven war narrative, positioning it as a Whoniverse standout.
Where to Watch
Available on BBC iPlayer in the UK; Disney+ worldwide rollout in 2026. Trailers showcase the Homo Aqua’s eerie emergence, building hype for this aquatic apocalypse.
