The main concept: there are some people with particular skills living in a world where they are not officially acknowledged, but they are nonetheless coerced into using said skills to perform particular jobs for the mafia-lords that rule the city.There is too little world-building to call this a dystopia, but we can fairly say that the world in which Blood Bound, that's not easy to accomplish.Olivia is able to track people from a sample of their blood. Everything begins when her friend Anne knocks on her door and demands that she avenges the death of Anne's husband, who has been murdered just few hours before.I hated the needy and whiny bitch on sight. But Olivia accepts the request quite graciously, given that a “demand” from her friend is actually a “do it or die” kind of deal; moreover, she has to do it at once and she has to work with her ex-boyfriend.The bitch (Anne, not Olivia).Just for putting a friend in such a position, Anne would have deserved a slow and painful death along the plot (but I'm not going to spoiler you and say if that actually happens or not).Olivia finds herself between the proverbial rock and hard place, because fulfilling her friend's request can cause (and will cause) every sort of friction with her arrangments with the local mafia boss. Not to say anything about the forced collaboration with the ex.There's plenty of mystery, little fun but a lot of sass, a lot of thrill and a conspicuous amount of sexual tension, even if there isn't a single sex scene in all the book (that's not to say there isn't sex, just that it's not overly detailed). Just writing this, I've decided to rate this five stars because really: what else do you want in a book?Originally, I gave this four stars just because of Anniethebitch. Ok, and because there are some huge question marks left unanswered, too.For example:1: Why don't they all move to another city/state/continent, where they wouldn't be subjects of the mafia system? I'm not saying they should (after all, I'm still living in Italy), but we don't know why they don't do it.2: How is the rest of the world organized, outside of the city? It's said that in the city there are two syndicated zones and an independent one. Are all the cities supposed to be the same?3: Why didn't Cam (male protagonist) try to talk to Olivia before these events? Six years is quite a long time to keep waiting for something to happen. Why didn't he move sooner?There are other ones that at the moment won't come to mind. And sure, there is also the problem with the ending. In series-related books some sort of cliffhanger is to be expected (if it were not so, the series would quickly come to an end). But I hate cliffhangers. Even little cliffhangers, like this one.But all in all this book had me captivated from start to end, and it was a solid good read. Hence the five stars.