When the body of a man is discovered at the foot of a cliff in the small resort town of Hari Cove, the police initially suspect a tragic accident, a misstep that cost the man his life. However, when it turns out that the victim was a former police officer and the cause of death is carbon monoxide poisoning, they begin a murder investigation. Manabu Yukawa, the physicist known as Detective Galileo, is in Hari Cove to speak at a conference about a planned underwater mining project and becomes embroiled in the case. Does the murder have anything to do with the small community's struggle to rebuild, or does it have roots in the town's history? In a series of twists that are as complex and surprising as in Higashino's brilliant, critically acclaimed work, Yukawa uncovers the hidden connections behind the tragic events that led to this murder.