In this world, being entangled by the "shadow of evil" means that you will be insulated from good luck, drinking cold water to stuff your teeth is a daily routine, and the lottery will always thank you for your patronage. Zhou Ning is such a recognized unlucky person, until she discovered that every small accident she encountered - such as just missing the bus that was destined to be in trouble, miraculously avoided a fatal disaster.
She came to an understanding with her "Shadow": it shielded her from the evil in the world, and she provided a place to stay. This strange symbiotic relationship was broken by an organization that hunted the "lucky ones". When the hunters regarded Zhou Ning as a "device of doom" that must be eliminated, she and her shadow discovered that they were facing a war about "destiny" itself.
Zhou Ning must learn to believe that in this world where everyone is chasing light, only the small shadow around her is her strongest fortress.