3.5 
 Originally posted at Vampire Book Club 
 Ever since he saved her from a mercenary attack, Lisette has been intrigued by the mysterious Zach. Her feelings are inflated even more when she starts having dreams about the man. She knows very little about him, but one the thing that is certain is that the leader of the Immortal Guardians considers him a traitor so Lisette doesn't dare voice her feelings to anyone, even those she's closest to. 
 Zach, too, has been interested in Lisette from afar and when he finally does appear to her in the flesh, he's been badly tortured. Lisette has no choice but to help the wounded warrior, but doing so will start her on a path there's no turning back from. In order to keep their burgeoning relationship a secret, Lisette begins to distance herself from other members of the Guardians. 
 While out on normal patrols the Guardians begin to notice that the vampires seem to be getting more capable and coherent, giving the Guardians a run for their money when fighting. Further confrontations reveal these vampires might have more knowledge of their opponents than the Guardians would like. As more and more mysterious coincidences appear it seems like someone within the Immortal Guardians may be a traitor. Keeping secrets is not in Lisette's best interest right now. 
 The mystery of trying to figure out who would betray the Guardians drew me into the story in Night Unbound. Just when I thought Dianne Duvall was revealing the culprit she would change directions again. It was refreshing that things didn't get too predictable. 
 Also, with the myriad of characters that have been introduced throughout the first five books, Duvall does a great job of including little snippets of each character (some more than others) so readers know that certain characters' stories don't stop with the end of their books. The camaraderie between the Guardians and their seconds provides for some funny moments, which is something I love reading in my paranormal romance and urban fantasy. 
 Unfortunately what both of these things did accomplish, however, was to overshadow Lisette and Zach. Lisette is one of the few female Guardians. She's had to watch both of her brothers find their loves while she sits idly by still aching from her disastrous marriage more than 200 years ago. Zach, what little we know, is an immortal of indeterminate age; we'll just say he's been around for a while. But being around for a while doesn't mean he's been around. He's just as surprised as Lisette that there are feelings between them. Their relationship, once established, deserved more than being pushed aside to focus on figuring out who the supposed traitor may be. I would have liked more of a balance, or it would have been nice if their relationship had been more entwined with the hunt for the traitor (an aspect that did begin to be incorporated but was quickly derailed). 
 All the makings were there for a great romance in Night Unbound. All the right sentiments were expressed and feelings spoken, but when it came down to it the relationship did not feel well rounded or fleshed out enough for me. Overall, the story pulled me in, just not for the reason I think it should have.