nine o'clock exactly
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 . Now , there lives in the lower story , that is to say , close to the street door , old Maitre Claude Patru with his housekeeper , a person of nearly eighty years of age , but still hale and active . Both of them heard Cardillac , according to his usual custom , come down stairs at nine o'clock exactly , close and bolt the door with a great deal of noise , go upstairs again , read evening prayer , and then -LRB- as was to be presumed by the shutting of the door -RRB- go into his bedroom . Maitre Claude suffers from sleeplessness like many other old people ; and on the night in question he could not close an eye , therefore , about half past nine the housekeeper struck a light in the kitchen , which she reached by crossing the passage , and sat down at the table beside her master with an old chronicle-book , from which she read aloud , whilst the old man , fixing his thoughts on the reading , sometimes sat in his arm-chair , sometimes walked slowly up and down the room to try and bring on sleepiness . All was silence in the house till nearly midnight ; but then they heard overhead rapid footsteps , a heavy fall , as of something on to the floor , and immediately after that a hollow groaning . They both were struck by a peculiar alarm and anxiety , the horror of the terrible deed which had just been committed seemed to sweep past them .