Katarina is an interesting companion, because she was written to die. In Terry Nation’s original script for this story, Vicki would have died in “The Traitors”, and I for one am extremely glad we avoided that reality. She deserves better as a character. But since she got written out in the last story, Katarina had to be hastily written in to fulfill her role in this one. Which...

Hang on, what? Katarina made one contribution to the plot: she gave Steven the pills from Bret’s pouch to heal him in episode one. Obviously, her death scene adds a notable sequence to the story, but what does it add in regards to the plot? Nothing, apart from resolving a plot point that was only introduced half an episode ago: the convicts on the convict planet (an underwhelming plot point anyways). I’m not going to lie to you: the role could have been entirely cut and it wouldn’t have changed much at all. I mean, I like Katarina! In the little we see of her, she’s friendly, kind, and views the TARDIS and everything she’s been interacting with in a fascinating theological light. But she’s given basically nothing to do by the plot, which big sucks when you consider she’s only a companion for four episodes.

Katarina’s death scene is very fast, but luckily it’s one of the surviving clips from the story (this story has a lot of surviving clips in it. The next one does not) which allows it a bit more gravitas. And the Doctor’s speech afterwards is simply brilliant and frankly extremely touching: the emotion Hartnell can carry, even through audio alone, is powerful. I nearly teared up. The choice from Loose Cannon to have a CG render of Katarina’s body floating through space...a bit less so. It’s just goofy. It adds nothing to the story and doesn’t look good—it just takes you out of it. It’s really rather sad that the most effect Katarina had on the story was her death, in retrospect.

It feels like I have very little to say about Katarina. She’s a companion largely defined by her exit and death, who really wasn’t given the chance to do anything else, which is too bad! I’ve heard that the show’s creators didn’t want to have a historical companion, because they felt that they would constantly need things being explained to them and it would drag down the story. And, I mean, on the one hand, Katarina gets a few things explained to her, but on the other, literally two years later they introduced Jamie from the 1700s, the longest-running companion of all time, and then Victoria from the...well...the Victorian era, who also stuck around for about a season. Hell, even Leela fills a very similar role! Like, this is a verifiably untrue hypothesis! Katarina could have been great! But they decided never to take that chance on her, which is a damn shame.