I wanted Mystery May to include a YA example, and I've been meaning to read John Green for a while, as he's both consistently well-reviewed and bestselling, a rarity for any author, but particularly one who writes books narrated by teenage boys (and he's got a wonderful ear for their dialogue, a rapid-fire mix of vulgarity and in-jokes). Paper Towns won an Edgar (the award named for Mr. Poe), so it was the natural choice.
The mystery here is the disappearance of Margo Roth Spiegelman, who's lived next door to Quentin Jacobsen their whole lives. When they were nine, they found a dead body together. Now that they're high school seniors, their paths rarely cross--he's a band nerd, she's a living legend, hatcher of schemes and haver of unbelievable-but-true adventures like joining the circus or hanging out with rock stars. But one night she shows up at his window, like she used to when they were kids, and talks him into "borrowing" his mom's minivan for an all-nighter of elaborate revenge (capped off by breaking into Sea World in the wee hours). The next Monday, she doesn't show up at school. And when she keeps not showing up, Quentin discovers a series of clues she's left, seemingly only for him, and decides he's the one meant to find her.
I'll admit I spent the first chunk of the book a little miffed by Margo, because boy is she ever a Manic Pixie Dream Girl, all wild and quirky and bringing timid Quentin out of his shell . . . and yeah, there are implausibilities to her character. Really, she ran away to Mississippi one summer and left behind an M, an I, an S, and a P in a bowl of alphabet soup? Ugh. But it's this very convention Green is playing with, it turns out. The more Quentin delves into Margo's life, the hazier she becomes, until he understands that not only is his conception of her flawed, it's only one of several layers of persona she's built up around her, wrapping herself defensively in audacity and riddles. The real mystery Paper Towns considers, then, is subjective existence--how well can we ever, even with the best of intentions, know another human being? Margo's true self, Quentin realizes, is both simpler and more complex than he'd thought: "[t]he fundamental mistake I had always made," he says, "and that she had, in fairness, always led me to make--was this: Margo was not a miracle. She was not an adventure. She was not a fine and precious thing. She was a girl."