Shaodi Yu, an orphan, is adopted as a result of of a murder case involving the deaths of his entire family. Because of some painful experiences, he refuses to speak. However, he has sharp insight; moreover, he becomes under the care of a pair of twin brothers in the police force, who also have a child currently in university. Yu Yin possesses yin-yang eyes, which allow him to see things ordinary people cannot. The two brothers happen to complement each other, and together they investigate various inconceivable incidents.