midnight
The next day , when M. de Bois entered , Maurice greeted him in a mournful tone . `` She did not come last night . I watched for her in vain . The ` sister , ' yonder , went as usual at midnight , and came back in the morning ; but , during the night , a stranger took her place . '' What could M. de Bois answer ? He gave a sigh of sympathy , but did not attempt to make any comment . `` She knows perhaps that my father is here , and she will come no more for fear of being discovered .