Generally, I have the attention span of a goldfish. At any given time, I am vacillating between 3-6 books, maybe more...depending on how unfortunate my reading choices happen to be at the moment. I lose interest easily...which says something about this book that I sat down, opened it, and read it through in one sitting. Holy cow, this was a lot better than I expected.It's not a perfect book by any means, it was rather too political at some point for my liking. By political, I mean the subplot of international espionage and politicians, not that the book had a heavy political agenda in its message (although there were a few digs here or there towards Republicans and Apple employees). However, overall this was a very fast-paced, action-filled book with believable, complex teenage characters despite the plot which, to my dubious self, initially sounds like a deadlier version of The Mysterious Benedict Society. The twists and turns are just unbelievable. The ending had my mouth hanging open, and the second half of the book was nonstop action. I was rarely bored, through the setup, even the weaker flashbacks, this book was absolutely engrossing.The premise, I admit, is a little far-fetched. We do not know the character's name. His identity changes from mission to mission, the details are always roughly the same. The MC gets a mission and a "mark," he befriends that mark's child, and gets close enough to kill them. Only with this latest mission, there's a problem: the mark's daughter. As I read this part of the summary, you can see my eyes slowly rolling into the back of my head. A girl. It's always a goddamn girl getting in the way. Geez. This girl better be worth it. And she is. And he is.I loved the writing style. There is no purple prose here. The writing is short, succinct, to the point. It is pretty clear that the author is a male, unlike other books I've read in which the male character was written by a male author, I can completely buy the fact that our narrator is a 16-year old adolescent. There is no Ethan Wates here; our protagonist is observant, but in a business-like manner. He notices body language, he notices suspicious characters, he sees the relevant details, he has been trained to detect abnormalities and inconsistencies. He doesn't notice a girl's wearing shoes that doesn't match her purse, none of that shit here. He is a trained killer and fighter and his way of thinking is absolutely consistent with his character."Accidents, illness, genetics, bad luck.There are a thousand ways to die."Our unnamed MC is known in the main arc of the story as "Benjamin." We are not given an entire back history of his past, but we do get glimpses of it in flashbacks. When he was twelve years old, his parents were killed by the Program, and he became initiated into it."Whatever I decided, my life was no longer my own. I could give it up forever and join my parents, or I could join The Program.Twelve years old, and I had to make a choice between life and death.I chose death.Ironically, it was what they were looking for. It showed them the level of character they were seeking, the list of personality characteristics appropriate to a potential soldier.Intensity.Black-or-white thinking.Stubbornness.Allegiance without regard to consequence.They took my allegiance and transformed it into something that would serve them."He is seemingly stripped of personality, adapting it to the situation as it fits. He observes a new environment first, assesses the mark and like a skilled spy, selects the best method and personality to adapt in order to infiltrate his target. We're not meant to love him, Ben is a highly trained killer. He has killed before, we watch him kill not even 10 pages into the book. He does so again and again, methodically, instinctively, but never maliciously or needlessly. He is a soldier, it is his job. Ben does the same with this situation, but the daughter of the new mark turns out to be someone unexpected. Ben is successful at getting close to the target...but to his shock, to his bewilderment, he just can't bring himself to kill his target.Sam (Samara) is not a typically fluffy YA female heroine. She is beautiful, yes; she is smart, yes, but she has suffered in her life with loss, and having been raised as the daughter of a very well-known politician. Sam is no simpering miss; she knows bullshit and a sycophant when she sees one. Sam is a challenge, a tough girl. "...passion plus intellect, with some deep emotional baggage beneath the surface." A bit stereotypical? Maybe, but she is well-written in her complexity, and I found myself loving her character. Sam doesn't buy the whole new-boy-falls-in-love act; she is not overly stubborn and bitchy, but she calls out bullshit when she sees it.Sam has a healthy dose of skepticism:"'I don’t know,' I say. “Something about you, I guess. I can see you’re different.'It’s a classic ploy. Express interest in a girl you just met. If you do it right, you can charm her, or at least pique her interest.'You're playing games,' she says. 'We don’t know each other, so how do you know I’m different?'So much for the classics."They do not meet cute. Ben and Sam clash, yet they see in each other a spark, something that draws them to each other. There is no insta-love as Ben meets her and assesses how to best get close to her, and as she sees Ben and gets the impression that he is smart-ass bystander lacking in intelligence. Yet, as they fight, the sparks fly, and they are drawn to each other on a deeper level than that of initial attraction.Their relationship is complex, they're not the core of each others' world, and that's just fine. It's a realistic portrayal of a teenage relationship where friends and others are involved, and the two people are not the center of each others' universe, despite their overall attraction. Besides the fact that Ben has a mission to kill her father, that is.The other characters in the book are well-done. The teenagers in the book feel authentic. There's drinking, there's sex, there's teenage mating behavior, but it is never outrageous, never done for the sake of portraying a typical teen stereotype and always feels accurate. The school environment takes place in an exclusive New York private school, and it is well-done. The teenagers are studious, and above all, fiercely intelligent; they debate, they are well-prepared for the cutthroat competition as is typical in a college prep school and I love that the author does not dumb it down and lump the teens in this book into a mass of illiterate, unthinking, uncaring clods.The action is so well-done, I am never lost. There were some weak points, like the flashbacks and one particular plot hole about his past that never got entirely resolved. I didn't like the subplot outside of the mission, it was a little too close to a few recent episodes of NCIS for my liking. I hope there will be a sequel, because I am highly interested in finding out more about what happened in "Ben's" past.