Summary

Twins brothers Woosin and Suhyeon lost their father in a murder case twenty-two years ago. Now a mystery novelist, Woosin finds out that the murder weapon was a diamond arrow called "Adamas." In order to find it, he enters the mansion of Jaegyu as a ghostwriter for his memoir. Suhyeon, now a prosecutor, reopens the case after meeting a reporter who seeks to reveal the truth of the incident.