Em is a twelve-year-old girl in a floating community off the Gulf Coast. Kaya is a political activist in a terrifying prison. They are pen pals. Em's wistful message in a bottle finds its way to Kaya, imprisoned above the molten lava of the Ruby Lake. Both are living precarious lives, at the mercy of societal, natural, and perhaps supernatural forces beyond their control. Kaya's letters inspire Em, and Em's comfort Kaya-but soon this correspondence becomes more than personal. Individual lives, communities, and even the fate of an entire nation will be changed by this exchange of letters. "Pen...