We read this story from Gabriel's POV, and we are not told everything about what's going on until Gabriel figures it out for himself at the end, so expect to be confused to an extent most of the way through. 
 There's something special about Gabriel though. One night, after playing with a new Dom, things during play take a surprising turn. When he wakes up alone, Gabriel runs away in fear. Then he notices the changes within himself, slight at first but slowly getting stronger. Even so, he knows something isn't right with him. He's not the same. 
 We meet him living on the streets after he's realized that people--well, not exactly "people"--are following him and he's gone into hiding from them and the Dom who did this to him. Only the Dom finds him and claims him once again. But he has to claim the Dom as well, and there are a lot of others after him to steal him away before he does. Frightened of everyone and everything, even at times his Master, Gabriel doesn't understand why he can't stand up for himself at all (and I didn't either, if that's how he felt)--that's not the way he is, not who he is--so what the hell is going on with him that he's acting this way. 
 Saying that he's a "human omega" doesn't give you the understanding into what that means. You have to live through it with Gabriel before you'll truly understand, just as he does. 
 My only grief with the story is that we don't get to see Gabriel settle into his new life and how that falls out in relation to who he used to be and thought he wanted to continue to be, to some extent. Gabriel has a lot of concerns that his Dom seems to gloss over or leave unanswered, even though we know Cal can feel them roiling within Gabriel's mind. That actually rather pissed me off about Cal--to know something was bothering Gabriel so greatly, but to not address it. I suppose it was because he didn't think Gabriel was ready, but to me that felt like holding him back, not helping him. For this it wound up as between 4-4.5 stars for me. 
 And Kari Gregg still writes some of the hottest (and longest) sex ever penned. And there's a lot of it in this book, but it really was necessary. Very. Very. Very necessary. ;) I would eventually enjoy seeing more set in this universe. 
 ETA: After reading some of the other reviews, I get the feeling that many who didn't like it didn't ever understand the warring human vs. Omega natures within Gabriel (which wasn't ever stated in so many words), or that Cal was being too overprotective in letting Gabriel discover it on his own instead of filling in the gaps. I think Cal should have explained it more, to build trust. He thought it would be too much for Gabriel, which caused the bond to take longer than it might have otherwise. People make mistakes. I forgave that in Cal; others didn't. *shrug* 
 In the end, it made sense to me, but if you don't get that from it, it wouldn't make sense, and I'd expect 1 or 2 star ratings then.