Chapter Four: No One Behind the Door

Shen Man's room remained as it had been fifteen years ago: dust blanketed the bed, one corner of the mirror was cracked, and the wardrobe still bore the marks Chenzhou had carved to measure his height at nine. No one was inside. The knocking came from an old heating pipe. A copper tab had been tied near its base, tapping the metal whenever the water pressure rose. Chenzhou crouched. The knot was new. Four digits were etched on the back of the tab: 0704. “Someone has been here recently,” Wanqing said. “Every room is cleaned,” Bai Yi replied smoothly. “There is dust on the furniture, but none in the keyhole.” Chenzhou removed his engagement ring and used its edge to pry apart the copper tab.