Xu Ci appears to be a gentle kindergarten teacher, but in fact he is the top killer "Shadow" in the underground world. During a mission, he accidentally rescued a child who was involved in a gang struggle. In order to protect this child, Xu Ci chose to hide his identity and live as an ordinary dad. But as the dark forces continue to pursue him, he has to gradually reveal his true face. In the process of protecting the child, Xu Ci discovered that the child had a mysterious connection with himself. When all the clues point to a larger conspiracy, Xu Ci is faced with a choice: continue to disguise, or become a demon with one thought and use the most extreme means to destroy all threats.
