‘Doctor Who’s Spinoff Changes Franchise Forever With Sea Devils’ Fate

Warning: This article contains spoilers for The War Between the Land and the Sea‘s finale and mentions genocide.Despite being a far grittier approach to traditional Doctor Who storytelling, spinoff The War Between the Land and the Sea is still undeniably part of the same universe. So, the miniseries’ finale has some pretty drastic implications on the larger lore that must be acknowledged by its parent program upon its return. Franchise head Russell T Davies, who’ll also be penning the script for Doctor Who‘s 2026 Christmas comeback special, now has some more loose ends to tie up. The War Between also comes with a terrifying finality in some ways.

The War Between‘s finale is the last Doctor Who effort to come from the BBC’s deal with Disney, which is now complete. Despite Doctor Who‘s very soft reboot ahead of the 2023 60th-anniversary specials, everything live-action that was made during the Disney partnership is also part of the main canon. This includes The War Between and its dramatic goings-on. Things like the immediate future of UNIT and the fate of a classic-era Doctor Who villain have been impacted by the spinoff, so it’ll be especially interesting to see where the franchise heads next and how it accounts for these changes.

The Shocking Genocide of Aquakind Is ‘The War Between’s Biggest Addition to ‘Doctor Who’ Canon

BBC

The clandestine operation, referred to only as “Severance,” is finally made known to the audience in The War Between‘s finale, and it brings the show’s titular conflict to an immediate halt. As it turns out, Mankind had designed a virus that could spread rapidly through the Earth’s oceans, infecting Aquakind and killing them on a huge scale. By the time the lethal virus has done its work, only 10% of Aquakind’s population remains. Once known as the Sea Devils, Aquakind has been part of the Doctor Who franchise since Jon Pertwee’s Third Doctor encountered them in 1972.

Now, the chances of Aquakind ever returning as a threat have been functionally reduced to nil. With so few remaining, Salt (Gugu Mbatha-Raw) and her fellow sea-dwellers don’t stand a chance in a direct conflict with the planet’s dominant species – humans. While the Sea Devils have only ever been used sporadically and haven’t shown up in Doctor Who all that often, the ongoing threat of their return has always been a possibility. After The War Between, while Aquakind could technically factor into future storylines, their presence would need to be accounted for in ways other than posing an actual danger to humanity. There simply aren’t enough of them left.

Kate Finally Explains Why the Doctor Generally Doesn’t Appear in ‘Doctor Who’ Spinoffs

Jemma Redgrave as Kate in The War Between the Land and the Sea

The Doctor does have a track record of having cameos in Doctor Who spinoffs, but only when the threat massively surpasses what the story’s core characters are capable of handling. Even when he does show up, he doesn’t tend to remain part of the spinoff for very long. Jemma Redgrave’s Kate Lethbridge-Stewart finally addresses this in The War Between. She explains that the Doctor once told her, “I save the human race, I don’t shape the human race. You can get that wrong all on your own.“

It’s a fairly generous generalization, but it does make sense. After all, The War Between is about a battle between two species that are native to Earth. It’s not the Doctor’s place to get involved. So, it’s logical that he’s absent from this particular spinoff. Going forward, if Doctor Who spinoffs similarly deal with threats that aren’t alien by nature, then it’s safe to assume that Kate’s explanation can be applied to account for the Time Lord’s absence. This doesn’t exactly explain why he didn’t step in during Torchwood: Children of Earth. Those familiar with that particular spinoff storyline will know that the Doctor should almost definitely have intervened.

Kate’s Mental Ending in ‘The War Between’ Sets up a Worrying Future

Kate aiming a gun in The War Between the Land and the Sea

The death of Christofer (Alexander Devrient) deeply impacts Kate in The War Between. After self-diagnosing herself with PTSD, she blackmails her therapist into doubling her medication when it’s suggested she’s to be temporarily relieved as UNIT’s commander-in-chief to recover. While it initially seems as though Kate is managing to hold it together, the finale’s final scene proves that the end of the Sea Devil threat hasn’t allowed Kate to move on from battle mode. Plus, it makes Christofer’s 2023 introduction in Doctor Who especially important. When a runner drops a plastic bottle on the beach, Kate’s polite request for him to pick up his litter quickly escalates into the civilian being held at gunpoint when he refuses to obey.

The War Between the Land and the Sea‘s finale marks Jemma Redgrave’s 21st appearance as Kate Lethbridge-Stewart.

While it’s an understandably frustrating scenario given everything that’s just happened, Kate’s reaction is way too extreme. As the leader of one of the planet’s most powerful and influential organizations, it’s very worrying that she hasn’t properly processed the loss of Christofer, and seems to be taking those unaddressed emotions out on those who don’t deserve it and in ways that aren’t befitting their actions. If this version of Kate is the one who shows up in Doctor Who‘s future, it’ll be interesting to see how the Doctor reacts during their next team-up, and what damage UNIT may do in the meantime.