Since Doctor Who's 2005 revival, the show has produced several episodes that barely feature the Doctor, and these "Doctor-lite" stories can often be surprisingly good. One episode from this very specific group of Doctor Who adventures doesn't get the love it deserves, but it did open the door for showrunner Russell T Davies to allow his most recent spinoff to take shape.
The War Between the Land and the Sea aired its first two episodes on the BBC iPlayer in the UK on December 7, 2025. It will eventually be available on Disney+ outside the UK, but not until 2026. The spinoff focuses on a mixture of new and familiar characters and adopts a vastly different tone than Doctor Who. However, the franchise's parent show teased what The War Between would be like incredibly recently.
FULL SPOILERS below for The War Between the Land and the Sea, Episodes 1 and 2!
How Doctor Who's "Lucky Day" Set Up The War Between the Land and the Sea
Ncuti Gatwa's Fifteenth Doctor was functionally absent from three Doctor Who episodes during his time leading the show. He had severely reduced roles in "73 Yards" and "Dot and Bubble" in his first season, but it was his meager screentime in "Lucky Day" that's more relevant here. Like "73 Yards," the cast of "Lucky Day" was led by Millie Gibson's Ruby Sunday. While neither episode had any direct involvement from the Doctor, "Lucky Day" stands out for being far more UNIT-centric than "73 Yards."
Most commonly associated with protecting the Earth from extraterrestrial threats, UNIT took on unconventional challenges in both episodes. In "73 Yards," it was a mysterious future version of Ruby created by some sort of unknown supernatural force, and in "Lucky Day," it was a right-wing organization called Think Tank, which was trying to out UNIT as a fake and necessary organization created to keep the public in line with fear of aliens that don't really exist.
Of course, UNIT very quickly leaves Ruby to deal with the phenomenon by herself in "73 Yards," and that timeline ends up being erased anyway. Inversely, UNIT becomes one of the leading forces in trying to suppress Thank Tank's damaging ideology in "Lucky Day," despite the task not being the kind of thing that Kate Lethbridge-Stewart (Jemma Redgrave) and her team are usually landed with. I loved seeing the idea from "73 Yards" revisited in both Doctor Who and its new spinoff.
The Doctor's absence from "Lucky Day" & The War Between makes complete sense for the same reason
Watching UNIT engage in something that isn't within their traditional wheelhouse is part of what makes "Lucky Day" so unique and entertaining, and The War Between the Land and the Sea deepens that premise by framing it as the main event. Furthermore, neither story has the Doctor leading the way, because it wouldn't make sense for him to do so. While he has an affinity for Earth, it isn't his homeworld, and it's arguably less acceptable for him to get involved in affairs that only affect the planet's native species.
In other words, appearing during the fake news about alien hoaxes in "Lucky Day" would not have helped. The Doctor looks human, and so would only lend credence to Think Tank's insistence that aliens aren't real. Similarly, as a Time Lord, the Doctor has no real right to get involved in the negotiations between humanity and Homo Aqua, both of whom evolved and live on Earth. So, giving the Doctor a major role in The War Between would feel inauthentic and illogical, and having him as a side character would overshadow the spinoff entirely.
A key piece of behind-the-scenes trivia makes the connection between "Lucky Day" & The War Between even stronger
"Lucky Day" was written by Pete McTighe, who hadn't penned a Doctor Who script since his pair of episodes from Jodie Whittaker's time as the Thirteenth Doctor. With "Lucky Day" having such a unique tone and wonderfully weird approach to Doctor Who storytelling, especially with how UNIT was used, it makes sense that McTighe was chosen to work with Davies on The War Between the Land and the Sea.
McTighe has writing credits on three of the five War Between episodes. He wrote episodes 2 and 3, and co-wrote episode 4 with Davies, who wrote the premiere and finale by himself. Knowing this, "Lucky Day" seems even more like a backdoor pilot for The War Between the Land and the Sea, and I'm very glad that McTighe was recruited to once more stray from the path of what a story within the world of Doctor Who is typically capable of being.
The War Between the Land and the Sea is streaming in the UK on the BBC iPlayer. It will be available internationally on Disney+ in 2026.