Finally freed from the story arc, we can now get back to more regular doctor who stories. This is one such, bringing us a rather conventional plot of strange worlds and alien devices. There's a lot of strong incidental detail, mostly in a nicely realised alien world and some good supporting characters, but the book meanders for the first half and then has to rush to wrap everything up before the end.
It also deals with the doctor's lost memories. The resolution of this was not was I hoping for, but I didn't throw the book across the room, so it can't have been too bad