eleven o'clock in the evening
... That ended matters . `` Mazeroux and I retired to the hall passage , closing the door after us ; and M. Fauville remained alone and free to act . Nothing now could prevent the fulfilment of his wishes . At eleven o'clock in the evening , Mme. Fauville -- to whom no doubt , in the course of the day , imitating Sauverand 's handwriting , he had sent a letter -- one of those letters which are always torn up at once , in which Sauverand entreated the poor woman to grant him an interview at the Ranelagh -- Mme. Fauville would leave the opera and , before going to Mme. d'Ersinger 's party , would spend an hour not far from the house . `` On the other hand , Sauverand would be performing his usual Wednesday pilgrimage less than half a mile away , in the opposite direction . During this time the crime would be committed . `` Both of them would come under the notice of the police , either by M. Fauville 's allusions or by the incident at the Cafe du Pont-Neuf ; both of them , moreover , would be incapable either of providing an alibi or of explaining their presence so near the house : were not both of them bound to be accused and convicted of the crime ?