It's fine, I guess.  I enjoyed having a story focused on Nyssa and the Doctor along with the dark and lonely ambience the story easily established.  Part of that is owed to Sarah Sutton's great narration.  I think the problem is a little deeper though.  The story itself felt a little bland and predictable.  It really didn't stick with me in any meaningful way.  So it feels like a competently made and written Short Trip, one that was a very easy listen, but one that also didn't quite leave much of an impression on me one way or another.

I enjoyed this more than I was expecting. Nyssa can be hard to write for, as her role in the TV series was often little more than eye candy or a calm voice to contrast with outbursts from Tegan, Turlough, or Adric. I'm also not generally a fan of second-person narrative, which can feel like the author is telling the reader what to think. In this story, however, Nyssa's passivity and optimism work well with the psychological nature of the challenge, and the use of second-person is cleverly justified by the end of the tale.

There's an alien threat. It's Doctor Who, so the presence of some sort of alien is not really a spoiler. However, while listening to the story, I kept wondering whether the alien threat was really necessary. Either way, this was a pleasant listen.