I think I like Torey Hayden better as a writer of fiction. I don't get mad at her philosophy of psychology (or lack thereof), since that doesn't come up in this book.
David is a boy of 12, who has lived most of his life with his older sister, Lily, in various foster homes. Now Lily has been sent to live in a "home" (read "facility for juvenile delinquents"), and David is living in a new foster home on his own for the first time. He has learning disabilities and a stutter, so he's picked on at school, and he keeps a list of "The Very Worst Things" - the worst things he can think of to happen to a person. At the very top of the list is having no one - no family, no friends, not belonging anywhere. Then he meets Mab, another social outcast, and they develop a friendship as they work to hatch an owl's egg.
I really liked the character development in this story. Hayden obviously knows what it feels like for a foster child like David, for a girl like Mab, who's stuck in a class with kids older than her. Even some of the secondary characters like Granny and the caseworker, Mrs. Mellor, are well-written, interesting people. Some of the other characters, like the bully, Rodney, are less developed, and that's really the only major thing I didn't enjoy about the book; it felt like the story would have been even more enjoyable if Hayden had taken the time to develop these other characters more, drawing out the story a bit more. But overall, a good book for teaching younger students about friendship, and forgiveness, and dealing with disappointment and loss.