There are funny parts, like where their biology teacher tells them that, thanks to the PTA, "to keep my job, I can't say anything rooted in scientific theory." Memaw tells Ruth that she understands about seeing things that other people don't. "I see god, after all... over by the back door." Ruth says, "WHAT--" and Memaw says, "just kidding."
There are lots of downright tragic elements to this story. It is remarkable in that it is much more than a tale of coping with mental illness, however. It is about the way that we get on with our lives in the best way that we can, no matter what challenges we face. Parents are fallible, as are teachers and police officers.
I was a bit baffled by the surreal ending the first time I read it but liked it even better upon a second reading.