Rating: 3.5Quick Take: A solid opener for a brotherhood-centric paranormal romance series. I wasn't completely convinced by all of the story's twists and turns, but overall found a lot to like, especially in the characters' interrelationships.Review:Yay for yummy preternaturals! Or perhaps I should make that tall, hulking, intense, gorgeous and heroic preternaturals! This series opener hits all of the aforementioned points with its merry (or more appropriately, brooding) band of blood-sucking immortals.You may have noticed I just now avoided using the moniker of "vampire" to describe the entities upon which the Immortal Guardians series is centered. In this world, "vampires" are mindless, bloodthirsty creatures of the night, whereas "immortals" are those who possess a very particular genetic composition allowing them to avoid the less refined aspects of their sanguineous nocturnal condition. Needless to say, the immortals are the "good" guys and the vampires are the bad.Have you ever seen or heard of the independent film Before Sunrise? If so, you'll recognize a similar type of romantic structure, in which the two romantic leads--initially strangers--are thrown together for a short but intense (and revealing) period of time. Before Sunrise is one of my favorite movies, so I very much enjoyed the similar type of interplay in Duvall's tale. Here, the world distills to just the two protagonists (at least in their minds). They share such honesty with each other, resulting in a plausible and intriguing connection.For that reason, I enjoyed the first half quite a bit more than the second, in which the story's scope broadens and begins some serious world-building. The climax of the tale felt like a bit of a jumble to me, and there were some plot developments and resolutions that seemed more random than surprising or exciting. That said, I still liked the characters and the overall lore that was developed throughout the book.This book does a great job where character interrelationships are concerned; from the romance to the various friendships examined, there was plenty to be charmed by. The next book will inevitably focus on different protagonists (as is the standard practice in paranormal romances), but with this first glimpse at the cast's personalities and dilemmas, I'm supremely enthusiastic about what's in store.