It has been ten years since 21-year-old Kevin MacKenzie, Jr. ('Mac'), has been missing. A Columbia University senior, about to graduate and already enrolled in Duke University Law School, he walked out of his room in Manhattan 's Upper West Side without a word to his college roommate and has never been seen again. However, he does make three ritual phone calls to his mother every year: on her birthday, on his birthday, and on Mother's Day. Each time, he assures her he is fine, refuses to answer her frantic questions, then hangs up. Even the death of his father, a corporate lawyer, on 9/11 does not bring him home, or break the pattern of his calls.Mac's sister Carolyn is now 26, a law school graduate, and has just been hired as an assistant district attorney in Manhattan. She has endured...