I think great books, especially ones within a series, can be defined by how much they make you want to flip back to the first page (of the book, or better yet, the series) and start from the very beginning. Silence Fallen has me reaching for Moon Called. 
 As much as I like reading about Mercy interacting with the Pack, I LOVE reading about Mercy on her own! There were some really cute moments, a little twisty I absolutely didn't see coming AT ALL, and more depth into some characters we've only gotten a little info on before. I loved this book. LOVED this book.