Published in 1998, the book won an Edgar Award for best children's mystery and spawned a series of “Sammy Keyes” books for the author. It's got all the qualities kids like in a mystery, and for the person who wants to write in the genre, it's a must read. It will amply reward you.
Kids like to be smart, like to figure things out, love the “Aha!” moment when they get it without having to be told. And Samantha, the main character, provides them. The book has so many layers, so many levels, and the author doesn't spell things out. She let's the kids discover the story for themselves. There's the mystery of the hotel thief, of course, and the questions about Samantha's grandmother and why the girl has to pretend she's not there at nights and keep quiet during the day.
There's never a paragraph that says, “Samantha's mother dumped her on grandma and went away to be an actress, but grandma lives in a seniors only building and …” It's all there, spread out during the course of the story, and the author trusts her young readers to figure it out without her having to hold their hands.
And that's the kind of thing kid readers love. They don't want you to force feed them. They want to figure it out for themselves. The best book I've read in this regard is “Holes,” which never overtly comes right out and ties it all up in a neat package with a bow at the end. The kids put all the pieces together themselves, and that makes it all the more satisfying for them.
And there's plenty of other stuff in the book, the problems with starting middle school, and Officer Bosch, and Samantha's rich friend. All of them add depth and complexity. There's a lot in it for a book that is really a very quick read.
So that's two things I picked up over the weekend from “Sammy Keyes,” the need for layers and layers of story in the new project, and several ideas have already occurred to me, and the advisability of not spelling everything out.
Leave the kids something to go “Aha!” about.