Probably more 3.5 stars but I'm being generous. It was ok as a novella. I guess, I wasn't really wondering what was going on back home on Detritus. Spensa is such an interesting character that I like having her as the main focus. I didn't enjoy the more YA romance in this book. But I did like seeing more of the Doom slugs. Did I really need to read this? Not sure. But I'm glad I could check it off and go onto book 3 of the series.