The Missing Girl by Norma Fox Mazer

Now you see that he's carrying a hammer. He takes a nail out of his pocket and hammers it into the window frame. He takes another nail out of his pocket and hammers it in above the first nail. More nails. More hammering. You don't get it. Then you do.
He's nailing the window shut. He's nailing you in.
You never know who might be living in your neighborhood. You never know what sort of person is, for example, inviting you to help feed the ducks. Who's teaching you at school. Who's checking out your groceries at the store. You don't know anything about them do you. And that's the exact problem. Beauty (17, and not a REAL beauty), Mim (sixteen and quiet), Stevie (14, how could she change her name?), Fancy (12, talk talk talk), and Autumn (11 and the 'not special' baby) are being watched. They don't know it, no one knows it but the watcher. He's being good. He's not giving in. Until one of the girls walks up and pretty much invites themselves into his life. And just like that, a girl is missing, and in terrible danger.
You've never been locked in anywhere. You walk from the door to the window, from the window to the door. It's like you're a prisoner. No, you are a prisoner. You're in jail, and you haven't even done anything wrong.
This was the first thriller type book I've ever read. Ever. So bear with me, please. I did enjoy it. It was disturbing, a bit scary, and very entertaining. I liked the character switches (they are all written in a different way, and despite what my mom would think, it's not especially confusing.) and it was an interesting book. I'd give it three stars, and recommend it only to people who are 13 and up. (It was in the TEEN section, for tacos sake.)
That chub was not an athlete. Say she slept in the field last night. Say she realized how silly she'd been. Say they'd find her tonight, maybe on Route 11, walking back toward Mallory, tired, but glad to be found. Say all that, and try to believe it.