A comprehensive overview of the human immune system, with beautiful graphics that distills the essence of how our bodies work to keep us alive in a world full of hostile organisms, as well as the ways it can fail to do so. Dettmer favors telling a tractable story but is also very clear about when things are being simplified. I wholeheartedly recommend this book to everyone, though some of the language and imagery may not be appropriate for children younger than high school or so.