The execution shackles made a cold sound as they dragged on the floor of the detention center. Xiaoyu stared at the new dark red lines that appeared on the wall - like a map and some kind of code, but he was clearly trapped in a dream by sedatives last night. The court said, "There is a murderer hiding in your body," and the lawyer advised him to "admit it." Even the old orphanage photo beside his pillow was turned over and checked by the prison guards, who said, "There is something wrong with the pencil mark on the back." He wanted to wake up the "self" who knew the truth, but he could only drink water from the toilet, waiting for the shadow that was always crying to appear on the surface of the water. The doctor gave him a sedative on time every morning, saying it would "stabilize your personality." But every time the drug took effect, he would have the same dream. The person in the dream never looks back, but always says: "Wait another three days, until the last '√' is drawn, and you will know who the murderer is." But when he woke up, he found that there was always some wet soil between his fingernails, which was the same texture as the soil under the old locust tree. There was no locust tree in the yard of the detention center.