We knew that UNIT and its fearless leader Kate Lethbridge-Stewart would continue to play a role in Doctor Who’s universe. The show featured them heavily in its 60th anniversary specials, where Donna became yet another former companion to join its ranks. There’s even a UNIT spinoff in the works at Disney+. This season’s trailer showed the Fifteenth Doctor and Ruby at UNIT headquarters. But we surprisingly got a cameo with Kate Lethbridge-Stewart and UNIT in this week’s Doctor Who adventure. “73 Yards” focuses heavily on Ruby’s quest to figure out why a mysterious (and creepy) old woman is following her. The problem is, the Doctor has disappeared and she must figure it out on her own.
A year into her ordeal, Ruby is left cold and broken with no family and no Doctor. Oh, and this woman is still following her from 73 yards away. She finally links up with Kate, who meets her in a public place with a plan for her UNIT soldiers to capture the woman. Their conversation is brief with Kate wondering why Ruby didn’t contact her earlier. Kate believes that the Doctor went silent for some reason and wants Ruby to take her to the TARDIS. It seems she wants to offer Ruby a place at UNIT but that never manifests. When the soldiers get close to her, all their shielding tech fails. They, like everyone else, hear her say something and run away, as does Kate, who is wearing an earpiece.
We don’t see Kate nor UNIT anymore, so Ruby is left to live with the lady for a whopping 65 years. At the end, she’s an old lady who finally embraces the woman, who turns out to be her. Time resets and Old Ruby tells present Ruby to tell the Doctor not to step into that circle. We can assume that all is well once again. And we know we will see Kate and UNIT in the future.