I loved this book.  I started reading it at the end of May when I was just beginning to process the trauma of working through the first wave of the COVID-19 epidemic, and felt like I needed a love letter to New York City.  As fantastical as the premise is, it's not that hard to swallow.  (And yes, I do read a lot of speculative fiction, but this will probably go down easy with both those initiated to the genre and those not.)  

The real magic of the book is the characterization of the city through its avatars. Though some may complain they trade on stereotypes, I found Jemisin's exploration of the city's and boroughs' identities entertaining and enlightening.  Manhattan, for example, is a recent transplant from outside the city who comes for a finance job and instantly suffers amnesia and can't recall his own name.  Brooklyn is a former hip-hop MC turned city council member.  I won't give away the rest.

As with all good speculative fiction, the cogency of the world-building is one feat, but the ability of that world to reflect our own is the real art.  Jemisin uses the relationships between avatars to explore aspects of identity (race, ethnicity, gender, sexual identity), power, trauma, and loss, but also to explore what makes a city come alive (why do New York and a handful of others get the privilege of being born, while so many older cities do not?).  The novel ultimately centers around themes of inclusion and exclusion as the city struggles with its inner and external enemies. And the ending, which reinforces what makes New York City so distinctive and so great, made me proud to be a New Yorker.

I highly recommend this, and I'm looking forward eagerly to the next books in the trilogy.