I have read this book so I think participating in the poll is probably cheating. Michael Morpurgo writes incredibly sad children's books (and a lot of them are WWI related, now I think about it, he wrote War Horse, which is probably his most famous) with misleadingly cute covers and summaries and then 'holy shit' story lines. A lot of them do still manage to be pretty optimistic, though.

This is reminding me how much I like this book, I should track it down.