Heart-stirring human drama meets one of the author’s most daring tricks—A legendary fusion in mystery history.

For the first time in five years, Detective Takeshi Yoshiki of the Tokyo Metropolitan Police Department's First Investigation Division receives a phone call from his ex-wife, Michiko. Shortly after, he catches a glimpse of her aboard the departing Yuzuru No. 9 train—only for a body believed to be Michiko's to be discovered inside the train the next day.

Standing at the heart of the case is another baffling mystery: a murder at the Mitsuya Apartments, located deep within the primeval forests of Kushiro. Pouring his entire heart and soul into the investigation for the woman he loved, can Detective Yoshiki unravel this impossible crime?