This book was an interesting story that perfectly catered to questions that a reasonable reader would have when reading the main series. It did a fantastic job of cameoing main characters in the main series as well without making the book feel like it was some throwaway "see more of these characters" book. So many additional stories feel like they were made as a cash grab or to see more of our fav characters outside of their actually interesting story. This wasn't one of those at all. 

I love that this book doesn't back away from the villains being villains. There are moments that engender pity, understanding, and sympathy.... but so far it hasn't made the villains sympathetic. Instead, it just serves to make them understandable and interesting. I would honestly probably round this book up to a 5-star if it wasn't for the fact that I did feel a couple of explained things from the main series were... perhaps forgotten or not quite adhered to for this story. But honestly, the story was interesting and fun enough that I give it a pass for any perceived deviation from what we were given in the original series.