A retired Paris police officer recounts his baffling investigation into the sudden disappearance of a wealthy, eccentric collector who lives with his young wife and a troubled nephew. The narrative follows the unraveling of events after the collector fails to return from a late social engagement: domestic searches, puzzling silences, and contradictory clues prompt a formal inquiry that uncovers hidden tensions, ambiguous motives, and surprising psychological layers beneath outwardly respectable appearances. The account alternates procedural detail and personal reflection as the narrator's interpretations shift, culminating in an elusive resolution that leaves moral and emotional questions unresolved.