Inspector Gallien is investigating the rape and murder of two little girls. The only suspect is attorney Jerome Martinaud, but the evidence against him is circumstantial. As the city celebrates New Year's Eve, Gallien calls Martinaud to his office and interrogates him for hour after hour while Martinaud continues to maintain his innocence. We learn all about the evidence; we meet Martinaud's wife and learn all about the rift between the two; but will we, and Gallien, finally learn whether Martinaud is guilty?