This is the second of the Mercedes Thompson books. In Moon Called, Mercy recruited the help of her vampire friend, Stefan, to help out with some werewolf trouble that descended on the Tri-Cities. Now, the favor has come due, and it is Mercy's turn to help Stefan and the vampires -- a dangerous position to be in. Her partial immunity to vampire magic (a result of her walker heritage) may not be enough to help her when the vampire trouble turns into sorcerer trouble, which turns into demon trouble.Though I rated Moon Called a 4 (nearly a 5), Blood Bound was an easy 5 for me. It is good at being exactly what it's supposed to be. The tension is taut throughout, even when the story splits off and goes in a direction I wasn't expecting. The action and the danger were intense enough to lend a sense of urgency to the book, while never making it seem too extreme (leaving nowhere to go in the rest of the series). Briggs' characters are full and dynamic, even many of the minor characters; they're layered and interesting, but not distracting. There aren't tangential paragraphs describing rippling abs and long waving hair; what description there is, is to the point and effective.I continue to be surprised by Briggs. She makes choices that initial make me leery, and then she makes them work. I'm not used to that. Normally, if I stumble on something that I think is going to make me groan, it eventually does. In Blood Bound, the potentially groan-worthy thing was a split focus at the end. When the main trouble is over and the foe vanquished (is that spoilery? We all know how these things work out, don't we?), Mercy still has a bone to pick, a score to settle. It didn't really fall into the category of tying up loose ends because it was a bit too big for that. I expected it to be dealt with in the next book, and instead, a little mini-plot developed while Mercy pursued this new Big Bad. I really thought it was going to feel disconnected and tacked on, and instead it worked out perfectly. It fit the story rather than being wedged in to it, and it was just as engaging and proportionately dangerous and tension-worthy as it should have been. Briggs handles things well and either has a damn good content editor or a keen sense for it herself. Well worth the read.