The deposed prince Shen Zhao was demoted to the cold palace. His hand was cut off and only half of the sword was left. Little did he know that this remnant of the sword was the key to the mystery of imperial power. Lu Li, a female swordsmith, recasts the blade for revenge, but finds traces of the late emperor's blood among the iron filings. When the night rain in the cold palace drips on the blade, the sleeping secret guard, the sword manual of the mute slave, and the pipa string of the Jiaofang Secretary all point to an old regicide case that was burned. They used the broken knife as a guide and moved forward step by step, but they didn't know that the real hunter was waiting behind the dragon chair.
