I really liked this story!!! It's about shapeshifters who run an airline and are slowly replacing the human staff at an airport; there was a real tenseness with how the enemies can look like anyone, and the story kept up a real sense of mystery throughout most of its runtime as we wondered who was who and what the shapeshifters' ultimate plan was. And then in the last two episodes, Jamie hitches a ride on one of the planes, it goes into space, and things get really wacky.

I also really liked the airport setting. It's still a closed space, good for studio recording, but it allowed for a lot of diverse sets within the episodes that made the area really feel sprawling.

One thing about this story is that it's the final departure for Ben and Polly, two of the companions. Honestly I'm not too fussed; I was sad to see Steven and Dodo from season 3 go at the end of that season, but in Ben and Polly's case, I just can't seem to muster too much enthusiasm for them... they never really developed interesting personalities to me, and it probably doesn't help that most of their episodes are missing. I liked them, and they had some interesting moments... but they did feel underdeveloped compared to some other companions, and I'm kinda glad that Jamie can get a little more breathing room.