Passion Unleashed (2009) is the third book in Larissa Ione's The Demonica Series. If you like paranormal romance, Alpha males, some mystery/intrigue along with your romance, and hot sex scenes, give Ione's series a try if you haven't already. And, fortunately, although there is definitely a connection between all of the books (the heroes are brothers--same father, different mothers), you can read each entry as a stand-alone without being lost.
In Passion Unleashed, Wraith, who is part-demon and part-vampire (yum!), needs to obtain a charm from Serena Kelley, archaeologist and immortal as long as she maintains her virginity and, consequently, the charm in question. He needs to get the charm in order to defeat a poison given to him by an assassin sent by his dead brother (though I personally don't think he's actually dead and would love a future book featuring his redemption).
Not too surprisingly, what starts as a scheme to impersonate a bodyguard for Serena in order to seduce her, get the charm, and, essentially, cause her death, turns into so much more when Wraith realizes he actually likes this woman. Add the complication that not getting the charm means death for his brothers, featured in the two earlier books/great guys/men with families/saved Wraith from himself, in addition to himself, and what will Wraith decide to do? And what will happen to Serena?
Oh, and throw into the mix someone out to get Serena that she doesn't even know about, a Seriously Evil Creature hoping to take over the world, and the fact that Wraith has to turn to vampires for assistance when, although half-vampire, he's actually a vampire assassin, and you get the idea of how much Ione packs into each book in this series.
Learn more at the author's site here.
My overall personal rating of Passion Unleashed is a B+.