Our Dark Duet

A great if not perfect sequel in this series (a “bilogy”? “duology”?) with a similar structure as the first book.
It picks up after a length of time wherin Kate is in a new city with a new set of friends but still fighting monsters though she only knows what little combat training she learned in high school P.E. class (which she tends to mention a LOT). August is still in Verity but moving up the ranks of his adoptive father's taskforce, being emo about how emo but also how not emo he is, and has a new metal-plated violin with a bow that is also a sword??? (where they found a master violin maker that could also defy the laws of what makes a violin actually work isn't part of the story and also magic etc). They still think of each other - because this is Romeo and Juliet with monsters - but without the communication grid between cities, they have nothing but nostalgia to go on. Then things happen as they tend to do which causes a new monster to be formed, who then finds out about a larger food source in Verity via Kate so Kate uses it as an excuse to be a dick to those who gave her things for free and follows the monster because she's strong and brave and true and stubborn to the point of stupidity like all YA heroines. Anyway, more things happen that are exciting and then sad and then maddening and then more sad but also exciting. There's no happy ending here.