This is a really good episode - until it isn't.

I love the Doctor being creepy and unknowable in the beginning, the doubt and fear that he might be possessed or working for the bad guys. Trying to get Leela chased out of the citadel really leans in on that, but then you realise he did it to protect her, and I ended up rooting both for and against her - fantastic!

All the betrayal and misdirects start getting a little tiresome eventually, but by the time the Vardans are revealed it's obvious we're close to the end. (Possibly a nitpick, but they were described as Human, which makes me question how they got all their special powers, as the Sontarans don't have access to those either. They probably meant humanoid.)

But then the Sontarans arrive, and it feels like they were added in at the last minute when the writers realised they still have to more episodes to fill. I enjoy seeing more of the TARDIS, but this whole plot felt a bit tacked-on and meaningless.

I think my biggest gripe with the episode is Leela's send-off. She barely interacted with Andred up to that point and there was nothing leading me to believe she had any interest in him or in leaving the TARDIS.

I think that when I revisit this episode in the future I'll skip the last two parts and pretend they don't exist.