Doctor Who showrunner Russell T Davies was also the overseer of five-part miniseries The War Between the Land and the Sea. When penning the spinoff, Davies seems to have consciously avoided referring to the fallout of a huge retcon he made almost immediately after his return. The writing choice didn't massively influence The War Between's storyline, but it does sort of prove that Davies has painted himself into a very specific corner.
Davies' second spell in charge of Doctor Who began when he took back over from Chris Chibnall in 2022. After temporarily restoring David Tennant to the show's lead role, Ncuti Gatwa then stepped in as the Fifteenth Doctor. Davies hasn't been afraid to make some pretty bold additions to Doctor Who canon since he returned, and those decisions technically need to be accounted for in spinoffs to avoid inconsistencies.
The War Between the Land and the Sea doesn't feature the Doctor directly, but it does mention him a handful of times. Still, some recent twists, like the concept of bi-generation, didn't need to be considered when Davies was creating and writing the UNIT spinoff. However, there was one retcon that meant he needed to tread on narrative eggshells, and he avoided what would have been a surprisingly big plot hole by just writing around the retcon completely.
RTD's 2023 "mavity" retcon in Doctor Who explained
David Tennant's second full episode as the Fourteenth Doctor, "Wild Blue Yonder," shows the Time Lord and Donna Noble (Catherine Tate) accidentally land the TARDIS in a tree that just so happens to be in Isaac Newton's (Nathaniel Curtis) immediate vicinity. The Doctor and Donna massively misread the situation by making a pun about "the gravity of the situation," referencing the historical figure's discovery of the force in question.
What the Doctor and Donna don't realize before they leave is that Newton hasn't yet coined the term "gravity." But he DOES take an instant liking to the word...even if he misheard it. He ultimately mislabels gravity as "mavity" and seems very pleased with himself for settling on such a great name. With no one around to correct him, the word takes hold and becomes the official label for what was once known as gravity.
There have been several instances since, one of which was later in "Wild Blue Yonder," where the word gravity has been swapped out for mavity, locking in the mistake as part of Doctor Who's official canon. Even the Doctor doesn't seem to be aware that anything has changed, and doesn't flinch whenever he sees or hears the word mavity. It is, of course, something of a causality paradox, but Doctor Who is one of the rare shows that can get away with it.
The War Between the Land and the Sea never uses the word "mavity"
Canonically speaking, if anyone in The War Between had tried to say "gravity" or any of its derivatives, then it would have come out as "mavity," or one of the made-up word's derivatives. For example, Russell Tovey's Barclay Pierre-Dupont could have referenced the "mavity of the situation" with the Sea Devils. Maybe he could have told Kate (Jemma Redgrave) that she brought a sense of "mavitas" to proceedings. But that didn't happen. Because it would have been very silly. While it exists in the same universe as Doctor Who, The War Between adopts a vastly different tone. It's more mature, grittier, and finds its humorous moments in less quirky ways than its parent show.
So, Davies either made a conscious decision to avoid the word altogether, or he just so happened to never need it. Either could also be true of Pete McTighe, who helped write the spinoff. Additionally, it's a relatively obscure thing for casual fans to be faced with. If they missed that particular moment of that specific Doctor Who episode with Isaac Newton, it would be impossible to work out without asking around why someone just mispronounced such a common word, and why no one picked up on it.
Will Doctor Who ever be able to undo its gravity/mavity retcon?
Of course, high-concept sci-fi shows like Doctor Who can change just about anything with a creative enough writer at the helm. Davies was just injecting a little fun into the show when he changed the word for gravity, but two years later, it does seem tricky to find a believable way to undo the retcon. The fact that the showrunner probably had to avoid using the word altogether in The War Between is just the first sign that mavity needs to start packing its things.
That said, with the Doctor himself inadvertently causing the change and then being swept along with it like everyone else, there don't appear to be many obvious solutions to the problem. No one even knows that there's a problem at all. As far as literally everyone in the Whoniverse is concerned, gravity is called mavity and always has been. It's always a possibility that the show will just move on from the gag eventually, but Doctor Who fans are an astute bunch. I don't think the BBC would get away with sweeping this one under the rug.
The War Between the Land and the Sea is streaming now for UK audiences on the BBC iPlayer. It will be available internationally on Disney+ on an unconfirmed date in 2026.