First in the Alpha and Omega series by Patricia Briggs...
This actually starts with a novella in the anthology "On the Prowl", but I didn't read that whole book, just the part that applies to this book so for my purposes I'm treating that as a Chapter 0 in this book. It's in the same universe as her Mercy Thompson series and builds off one of the plotlines from the first book, Moon Called, in that series. It has to do with what happened when Bran sent Charles to Chicago to deal with whatever had gone wrong with the pack there.
This was one of those wonderful books that completely pulled me in and I just wanted to sit and read it and not do anything else! There's a number of really beautiful scenes that really grabbed me emotionally. The funeral part-way through (which is related to someone who dies in Moon Called) was one that made me completely lose it.
There's also bits sprinkled through it that flesh out some of what was happening with certain characters in Moon Called, mostly Samuel. There's more about why he decided to go stay with Mercy. And a lot more about the history of Bran and Samuel which was really cool. I liked learning more about their past and how they became who they are.
I really liked getting to know Charles more. He's such a secondary character in the Mercy series, and there's a lot to him! He has such an important role in Bran's pack, and it's a responsiblity he accepts, but it's a hard role to play. It holds him very separate from most everyone else.
So, a bit of plot stuff... first we wrap up some loose ends from Moon Called. Then there's people being attacked in Bran's territory and it looks like a rogue but it might be something more dangerous, some kind of attack on Bran's authority. So Charles has to go check it out. There's also stuff to do with one of the other very old wolves in the pack and what happened to his mate a couple hundred years prior.
I'm very much liking this author and I think I'm going to have to try one of her other series soon!