about midnight
This explained Fred Ryley 's strange words and attitude to me on the way from the station . The young man had been too timid to stop me . The matter was a trifle , but another idea that struck me was not a trifle , though I strove to make it so . My aunt had died about midnight , and it was at midnight that Diaz and I had heard the mysterious knock on his sitting-room door . At the time I had remarked how it resembled my aunt 's knock . Occasionally , when the servants overslept themselves , Aunt Constance would go to their rooms in her pale-blue dressing-gown and knock on their door exactly like that . Could it be that this was one of those psychical manifestations of which I had read ?