Fifteen-year-old Steven needs to explain something— everything—to his sister, Sam. She needs to know about Jenny from his new high school, and how the freckles on her arm make his synapses go crazy. She needs to know about eighteen-year old dropout Byron, all his fascinating ideas about chaos and coolness and trying to keep it together. And she definitely needs to know about what drastic measures Steven is now considering and why. He needs to get this all down, so that some day Sam'll know what happened to him—to all of them—last December.