this isn't a zombie book so much as a zombie framing device to explore damage and the difficulties of making yourself vulnerable in front of someone - of communication's pitfalls and the numbing effects of trauma. 
 there are people who believe that trauma builds character. these people have probably never experienced trauma. trauma does not build character, but how someone responds to trauma is the true and most telling test of character. 
 more often than not, trauma leads to a retreat. nobody is a fan of emotional outpourings, are they? or am i projecting again? so let's just talk about this character. sloane is not a fan of emotional outpourings. her father has been physically abusing sloane and her sister for years, and the two of them formed this intensely close bond that never allowed anyone else in. after her sister ran away, leaving sloane alone in the path of her father's rage, she had no support system in place to fill the gap, and became suicidal. 
 and then, the zombies attacked. 
 so what happens when the wrong people survive?? the ones who didn't want to survive before the world went to hell? 
 this is a fascinating character study. six teenagers holed up in a school, barricading the doors against the zombie invasion outside. alliances will form, resentments will fester, desperate hookups and confessions and all-around brokenness will ensue. 
 and sloane, watching it all, unable to break through her own emotional reserves to make herself vulnerable in front of the others. 
 is this what it's like to get close to other people - you do something insane together and then you have to share everything even if you don't really want to? 
 she grows so much as a character, and it is painful and sad and you just want to be there with her, holding her throughout it all. not that she'd let you. 
 the other characters are great, too. this is not a one-person show. it manages to rejuvenate the YA-survival genre for me, like a cross between the breakfast club and a way more intense Trapped. 
 one character mourns his life, and how with nothing left in the world, his opportunities to become something have pretty much ended. 
 "...it's nothing. i thought it could be something, i mean, eventually." he finally looks at us. "my life. i thought - but i mean...it's nothing." 
 how absolutely shattering to realize, at fifteen, that your life has meant nothing and is essentially over. GAH! 
 and how clear-eyed sloane is through it all, as she thinks of a future she is still not sure she wants any part of. 
 when this is over, society will need entertainment to get past it. we'll make movies about it, hundreds of movies, and in every one of them, we'll be the heroes and the love interests and best friends and winners and we'll watch these movies until we are so far removed from our own history, we'll forget how it really felt to be here. 
 that insight is very rare in these typical survival novels. often, it is just all about the clinging to a member of the opposite sex for validation or comfort. and there is some of that, here, but it is way more charged than is typical. there is an immediacy and a desperation that is deeply written and felt by the reader. 
 and thank you for the realism: 
 the thing no one tells you about surviving, about the mere act of holding out, is how many hours are nothing because nothing happens.they also don't tell you about how you can share your deepest secrets with someone, kiss them, and the next hour it's like there's nothing between you because not everything can mean something all the time or you'd be crushed under the weight of it. they don't tell you how you will float through days. you autopilot, here but not really here, sleepwalking, and then every so often you are awake. 
 god, i am so tired of import. there is an awful lot of sleeping in this book. and silence. and yet it is not boring to read - this is such a fast-paced book. but the reality of how boring it would be to survive is much appreciated, and the true fact that not every kiss is the beginning and end of everything. a kiss can be, in fact, just a kiss... 
 and this. the ramifications of the last two sentences in this quote are quite easy to overlook if you haven't read the book, but: 
 i am caked in mud and my hair is straggly and knotted from the rain. my lips are bruised. there are cuts and scratches on me that i must have gotten since leaving the school but i don't remember how. she won't recognize me when she sees me. i look like someone who has survived. 
 you should read the book. 
 if nothing else, read the first chapter, which is a triumph of buildup and utter utter chaos. i cannot remember ever reading a better opening chapter in all my days.