This review originally appeared at http://bellesbookshelf.blogspot.com/Chain Reaction is the final instalment in Simone Elkeles' Perfect Chemistry series. After following the exploits of his two older brothers, this book focuses on Luis, who we first met in Perfect Chemistry when he was 11. At first I didn't think I'd be that interested in Luis because, well, he was a kid like, five minutes ago, and that is so not hot. But he's all grown up in Chain Reaction and, like his brothers before him, he is smokin'. But unlike Carlos and Alex, he's a good boy on the outside as well as the inside. As the book opens, the closest Luis ever gets to danger is rock climbing and the other extreme sports that give him the adrenaline hit he craves. That is, until his mother decides to up and move him back to Fairfield.Yeah, that's right, the woman chooses the town where her husband was murdered and her eldest son was nearly killed as the ideal place to move to, with her 17-year-old son in tow.OK, OK, so the Latino Blood have supposedly fallen apart and the cops have literally moved in to the neighbourhood, but seriously?! It doesn't take long for the shit to hit the fan. This mother fails at, well, being a mother. She made me So. Freaking. Mad. And her excuse for moving back to Fairfield? She wants to be closer to her grandchildren (that'd be Alex and Brittany's kids - but that's a whole 'nother rant), coz she cares about them... apparently more than the safety of her teenage son. Her actions are even less excusable when a family secret connected to Fairfield is revealed later in the book. Argh!But enough of my ranting. At least on the topic of Mama Fuentes, anyway. Because I do have another one to get out of the way, as I alluded to above. That is... WTF happened to Alex and Brittany in this book?! It opens with their wedding, something you'd think would be a lovely, romantic, emotional event, given everything they've been through and how much they love each other... and it's a freaking circus. Mainly because Alex decided that they'd be living in Fairfield again after the wedding, because he's been accepted into graduate school there and Shelley is being moved to a facility nearby. None of which he's told Brittany about, let alone consulted her on. She finds out at the altar because Luis objects, refusing to let Alex start his marriage on lies.10 points to Luis. Minus eleventy-billion for Alex. He didn't even feel like the same character at that point. What makes the whole thing worse is that it makes zero sense - surely he and Brittany had discussed their future plans?! And what about her graduate school? I'm assuming she furthers her education as well, because apparently together they're a hot-shot team who discover a miracle cure, if the Perfect Chemistry epilogue is anything to go by. Then again, according to an interview with Elkeles, Brittany pops out six kids in quick succession, so maybe she's too busy for a career, or anything else - an issue that's unfortunately not touched upon in the books. Then there's the curious fact that Alex knows that Shelley is being transferred, but Brittany doesn't - Alex, who Brittany's parents think so little of, they don't even show up to their wedding. Yeah, that makes total sense.Obviously, I had a few issues with this book. But now that I've gotten them out of my system (are you still with me? Thank you kindly for your patience), I will say that, believe it or not, I did enjoy Chain Reaction. Luis is quite lovely, and takes after Alex, which was definitely attractive. I also liked Nikki, the girl he's drawn to, though I found her a little hard to connect with. But this was part of her character - due to certain painful events in her past, she puts up a wall between herself and everyone around her. So, while I couldn't exactly get under her skin, I could understand where she was coming from and sympathise with her.Still, I have to say, I was a little disappointed that, seeing as Luis was supposed to be the "good" Fuentes brother, the tables weren't turned in this book and it wasn't the girl who was the "bad" one in the relationship, as I'd kinda been hoping. Alas, Nikki is still the good girl from the right side of the tracks, and poor Luis is forced to retrace the destructive path his family had trod before him. That said, I was glad to see Chain Reaction did have a different tone to its predecessors, and even the narrative pace was altered from the one that was set in both Perfect Chemistry and Rules of Attraction. It was also nice - aside from the crapness that was the wedding - to see Alex and Brittany and Carlos and Kiara again, all loved up and happy. So, even with a few hiccups, Chain Reaction was a great end to an addictive series. Though my ranting might have you believe otherwise, I came away pretty damn satisfied.