Twenty-three years ago, Sumi Otonashi was killed in a mugging gone wrong. Or was she? Out of nowhere, her husband Gôichi reveals to his heirs that he killed her--and challenges them to figure out how. But can they reach a plausible explanation without knowing he contracted a spectre to do the deed? And what will their own buried secrets bring to light? Kotoko will have to judge the heirs' solutions, and lead them to the right answer...