I truly like this book, however I have some qualms with it.
The beginning of the book was a great way to tackle the fuzzy and disorienting feeling that comes after a large incident. The writing flows like a mind running in circles, panicking but exhausted (the style of the writing throughout the book had me immersed). I wanted there to be more of an influence and an explanation about the illness, the FISTS, and the government in general after they were introduced. The framing really had me believe it was going to play a larger role than it did. I feel like it was ultimately used more as a plot device rather than an aspect of the plot that could be further explored and extrapolated to give Calypso's final decision infinitely more meaning.
Calypso's time being a free runner ties into this same problem. The impact of all of her outside discoveries could have amounted to so much more; she is seeing the world uninhibited for the first time, caring about Furball contrasted with seeing animals slaughtered in the streets. We don't see that drive at the end of the book. They mention what happens to the kids who got caught and chipped like Dair, but we don't see mention of wanting to protect animals like Furball, or the hardships that come with the isolation that she encountered.
It sounds like being a free runner taught Calypso some parkour and a few survival skills that helped her while she was a ghost, but it struck me more as a child playing pretend and early teenaged rebellion being used to have her meet Dair. Their pairing didn't further her story as a member of the free runners or the resistance either, it was convenient for them to pair up. She simply gained the bottle cap and the watchful eyes of Alfie, when her fight could've strengthened her feeling of ire towards Vern and the will to continue to do something. Drawing similarities between him and the corrupt government, seeing the fact that her and Little Bird were both just as isolated as she was while being a ghost makes her decision to live all the more worthwhile. It removes the vague ability to do something, and replaces it with acknowledgment of what those problems are and why they are harmful. It allows her to have already done something.
All of that being said, I do like the understated mentions of Vern and what Calypso's situation ended up to be. Gathering bits and flashes of memories really drove home the point of abuse being often silent and hard to notice if you're not looking for it. Furthermore the extended metaphor of Little Bird being exchanged for 'Mom' at key times was brilliant. The handling of trauma was graceful. For any young teen or older teen, this could be incredibly valuable in handling life's hardships.
In conclusion, the book was a good read, I do recommend.