Stefan got a lot page time in Blood Bound. It started with Stefan called in the middle of the night requesting Mercy to accompany him to confront a new vampire that came into their territory. She's only suppose to go as a coyote and bear witness for Stefan. Of course, as it turns out the vampire, Littleton, is also a sorcerer cum demon. Stefan's memory were altered making him believes he killed someone, but Mercy being a skinwalker, was not affected by it. They both barely manage to escape the ordeal.
There were multiple homicide and violence occurring within Tri-Cities and Tony, the cop was concerned it might be link to the fae. The wolves pack decided to aid Stefan for the Littleton hunt with Warren ended up severely injured and Stefan missing. We got some Warren-Kyle moment here, my favorite gay couple. During this crisis, Mercy also realize that she have authority above Daryl and Warren, who are both Adam's second and third, by being his mate. Adam declare her mate during the first book to keep her safe from his pack.
The romance in this book is very subtle and we have to look for little hints here and there. Mercy mentioned that she went on three dates with Adam between Book 1 and 2, but we did not got the play by play. Not fair! I want details not summary. Anyhow, we got two Mercy-Adam scene in Blood Bound. The sparring session with Adam at his garage was HOT! I wonder what will happen with Jesse didn't pop up. On the other hand, the Sam's depression and self-loathing on his bed with Mercy comforting him was kinda heart-felt too.
Although Mercy keep telling herself that she care for both Samuel and Adam, but I'm confident that she will end up with Adam. When both Sam and Adam were in the same room with her, she mentioned that looking at Adam is way dangerous for her well-being and switch her attention to Sam instead, because is safer. I think that's a dead give away. The love triangle here is well handle as in you won't feel like strangling someone and Mercy didn't sleep with any of them. She didn't reject Sam because he is still an important person in her life and she doesn't want to hurt him. On the other hand, Adam is an overbearing Alpha, and she doesn't want to risk losing herself and independence by being with him. Anyhow, Mercy should make up her mind soon. I was surprised that both the male wolves didn't start tearing each other throat out. They are way too patient.