Review copy provided by the publisher. Also the author is a friend, as you will find out if you read to the end and see that I am in the acknowledgments for the honestly light and easy work of being Brandon's pal.

Good news for those of you who wait until a series is complete to read it: this is the second book in a duology! So you can just pick up Catalyst and Castoff and read them together, if you haven't yet. I'm going to try not to spoiler the first book too much, which is going to leave me vague, because this is definitely my favorite kind of sequel: the kind where the consequences follow on hard and fast from the first book. Happily for those with shaky memories, there's a quick summary at the beginning of this one.

So there are airships! There are strange vast somewhat personified forces! There are people working out their relationships in the face of personal and social change! It's that lovely kind of fantasy novel that almost might be a science fiction novel in its concern with human interactions with truly alien intelligences. I love that kind. I want more of that basically always. And if it can come with airship adventures alongside the ponderings of the nature of intelligence and caring about others, even better. Very glad this is about to make it out into the world so I can talk to more people about these books.