The story begins with what should be an open-and-shut case. Kaji, a former police detective with a sterling character and unblemished record, turns himself into the local police, saying that he has murdered his Alzheimer's-afflicted wife. Shiki, a former colleague and master interrogator, is pulled off a big case to question Kaji. But though Kaji owns up to his crime, he refuses to say what he was doing in the two days before he turned himself in. In police jargon he has delivered only "hanochi (half a confession)."