The BBC and Disney may have announced they’re going their separate ways after two seasons of “Doctor Who” — the show will return with a Christmas special in 2026 — but there’s still one more collaboration to come. The famous Time Lord is sitting this adventure out, but “The War Between the Land and the Sea” is very much a part of the Whoniverse.

Following in the footsteps of previous “Who” spin-offs “Torchwood”, “The Sarah Jane Adventures”, and “Class”, the new five-part series resurrects classic “Doctor Who” monsters, the Sea Devils, aka the Silurians’ watery cousins. They’re not happy about the way the human race has been mistreating the oceans, and are ready to take the fight to the land.

Long-serving “Doctor Who” boss Russell T Davies is the brains behind a new drama that’s targeting an older demographic than the Doctor’s ongoing adventures in the TARDIS. He’s also assembled a big-name cast — including some familiar friends from UNIT — for a series that’s set to make its long-awaited debut in December 2025. Here’s everything you need to know about “The War Between the Land and the Sea”.

Empire in November. “It’s very 2025 in its bones. We even deal with the water companies and their profiteering bosses, laughing in our faces. In a series about the water you have to!”

Radio Times. “I had this idea separately first. But weirdly, it needs the ‘Doctor Who’ setting. If I just go and pitch this cold, saying, ‘There is a race of creatures that live in the sea…’, they’d say, ‘Really? You sure?’ The pre-existence of the Sea Devils takes all the problems out of it.”

Any fans watching the Sea Devils’ previous appearances (in which they looked more like bipedal turtles than humans) will have noted that the species has been through something of a makeover for “The War Between the Land and the Sea”. While the first trailer (see below) features a brief sighting of a more traditional member of the species, lead Sea Devil Salt (Gugu Mbatha-Raw) looks distinctly more human than her predecessors — an evolution akin to the glow-up given to Madame Vastra and other Silurians in the new “Who” era. It’s not yet clear whether there’s an in-universe explanation for this new, more human styling — is Salt a homo sapien/Sea Devil hybrid, perhaps? — or whether it’s a storytelling decision to make it easier for a pivotal character to express her emotions.

One other thing to note about the latest generation of Sea Devils: Davies has revealed that, I the new show, “It’s racist to say Sea Devil” — apparently they now prefer to be called “Homo Aqua”.

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The first teaser debuted on May 31, 2025 (see above). In the “The War Between the Land and the Sea” trailer introduces the key players in the drama (Barclay, Salt, some friendly UNIT faces), as well as military hardware, epic political meetings, and what appear to be Sea Devil eggs. There are also, as you’d expect, plenty of shots of both the land and the sea.

“We could make a difference, you and I,” Salt tells Barclay in her voiceover. “End the conflict between our species. Before it’s too late.”

Unfortunately, Barclay appears to be rather less certain about his suitability for this unexpected new role: “I don’t know why you chose me, for any of this,” he counters.

He has until December to work that out — the fate of two worlds could depend on it…

Loki“, “Surface”) was Tish Jones, sister of “Doctor Who” companion Martha, in the third season of the show’s 21st-century revival.

Tovey will play Barclay, a low-level UNIT operative who unexpectedly becomes humanity’s representative in negotiations with the Sea Devils. Mbatha-Raw, meanwhile, is buried under extensive prosthetics as Salt, a member of the Sea Devil delegation who makes waves at a global summit on the Thames.

Jemma Redgrave is back to head up UNIT in her recurring “Doctor Who” role as Kate Lethbridge-Stewart, alongside fellow “Doctor Who” vets Alexander Devrient (the sensitive face of UNIT muscle, Colonel Christofer Ibrahim) and Ruth Madeley (scientific advisor Shirley Bingham).

Traveling further back into Whoniverse history, Colin McFarlane reprises his “Children of Earth” role as General Austin Pierce, a representative of the US military. Going on previous form, don’t be surprised if Pierce’s presence gets in the way of peace negotiations.

Other members of “The War Between the Land and the Sea” cast — exact roles yet to be officially confirmed — include Adrian Lukis, Patrick Baladi, Francesca Corney, Mei Mac, Vincent Franklin, Waleed Hammad, Iestyn Arwel, Hannah Donaldson, Manpreet Bachu, and Ann Akinjirin.

73 Yards” and “Dot and Bubble“, is the director for all five episodes of “The War Between the Land and the Sea”. Lorne Balfe (whose numerous screen credits include “Black Widow”, “Mission: Impossible — Dead Reckoning”, and Wallace & Gromit’s most recent outing, “Vengeance Most Fowl”) is on soundtrack duty.