Christopher Snow is the best-known resident of 12,000-strong Moonlight Bay, California. This is because 28-year-old Chris has xeroderma pigmentosum (XP)--a light-sensitivity so severe that he cannot leave his house in daylight, cannot enter a normally-lit room, cannot sit at a computer. Chris's natural element is the night, and his parents, both academics, chose to live in Moonlight Bay because in a small town Chris can make the nightscape his own--roaming freely through the town on his bike, surfing in the moonlight, exploring while most people sleep.But Chris's brilliant mother, a scientist, was killed in a car accident 2 years ago, and as the book opens his father, Steven Snow, is dying of cancer; Chris's protected life is about to change forever. We meet Chris as he is carefully preparing himself to go out in the late-afternoon sun to visit the hospital. In his last moments of life his father tells Chris he is "sorry" and that Chris should "fear nothing"--cryptic words that Chris cannot really relate to.