nine o'clock
` My master wished it so . ' ` And what had Master Cardillac to do in the streets so late ? ' ` That I can not say . ' ` But he was never in the habit of being out after nine o'clock at other times , was he ? ' At this Olivier hesitates , becomes confused , sighs , shed tears , vows by all that is sacred that Cardillac _ did _ go out that night , and met with his death . Now observe , Mademoiselle , it is proved to the most absolute certainty that Cardillac did _ not _ leave the house that night , consequently Olivier 's assertion that he went with him is a barefaced falsehood . The street door of the house fastens with a heavy lock , which makes a penetrating noise in opening and closing , also the door itself creaks and groans on its hinges , so that , as experiments have proved , the noise is heard quite distinctly in the upper stories of the house .