Micah -- the unreliable narrator of this tale -- is a compulsive liar from a fraught background. Poor and biracial, she attends a posh New York alternative school through a scholarship. Her mother is a runaway, her father is from a reclusive back-woods family of illiterate survivalists, and so it's no surprise that Micah's identity is a little messed up. But Micah isn't just confused: she's deliberately confusing, a compulsive liar who fools everyone around her over and over (she is mistaken for a boy on her first day of school and so she undertakes to live as a boy, lasting days before she is found out).
But Micah's lies start to unravel when the boy she is secretly dating -- he is publicly involved with the most popular girl in school -- is murdered. As the school panics and the social order turns upside down, as Micah grieves, she is also found out, scapegoated, and suspected.
That's the setup. So far, it's your basic YA fare: complicated relationships, complicated identity, fraught situation. But Micah's circumstances grow progressively odder, as Larbalestier twists and turns the story in ways that are decidedly science fictional (or possibly fantastic) and that make this into one of the most original, oddest, and ultimately satisfying YA books I've had the pleasure of reading.
I wish I could say more. There are so many surprises in this book, and they serve to tell such a complex and delicious story of love, identity, authenticity, revenge, justice, class and race, that I don't want to give anything away. Indeed, if this book has a failing, it's that it's nearly impossible to explain what's so great about it without risking some important spoilers. So you'll just have to trust me -- this is worth the price of admission and then some.