There’s much speculation that Kate Stewart, the daughter of Brigadier Lethbridge-Stewart from Doctor Who and the current head of UNIT, might die in the upcoming spin-off show, The War Between the Land and the Sea.

This comes after something actress Jemma Redgrave said about playing the character in the related programme. However, it could also mean that there could be a significant status quo change for Kate which would impact Doctor Who.

Jemma said:

“If she survives this series, I don’t know where she can go next. But I’ve had a most extraordinary time and journey with this character and through different series of Doctor Who and now through this series.

“And every time I get the call, it feels like another gift. Long may it last.”

Now, I don’t think this means she’s actually going to die in the show. I do, however, think something could change for her, perhaps in a personal capacity but perhaps related to her position in UNIT.

Writer Pete McTighe added to this theory, by saying:

“The character of Kate Lethbridge-Stewart… I think if you’re a huge fan of Doctor Who and you know that legacy character and you love that character like I do, I think you’ll be very surprised about the journey that she goes on through the show. Her character arc, in particular for Doctor Who fans, is probably the most surprising.”

That feels like a change of heart or something similar, doesn’t it?

Kate was first seen in the 1990s spin-off, Downtime, but first appeared in Who proper, played by Redgrave, in 2012’s The Power of Three.

It would be a great shame for such a legacy character to bite the dust in a spin-off show, especially as she’s not been very effectively utilised in Doctor Who recently, except perhaps in 73 Yards and, more so, Lucky Day. Plus, Jemma is lovely, so we’d like to see more of Kate!

The War Between the Land and the Sea begins on 7th December with a double bill in the UK, and will stream on Disney+ outside the UK in early 2026.