nine o'clock
He was healthy in every particular , and his destruction remained , so far , inexplicable to science . Hardcastle had died in a syncope , as the other victims ; that was all the most learned could declare . Impressed by these facts , the four made ready , and Lennox observed that they neither drank during their meal nor smoked after it . At nine o'clock they began their work of the night , but invited nobody to assist them , and begged that they might not be approached until daylight on the following morning . Dr. Mannering took it upon himself earnestly to beg they would abandon the vigil . Indeed , he argued strongly against it . `` Consider , gentlemen , '' he said , `` you are now possibly convinced in your own minds that the source of these horrible things is to be found outside the Grey Room , and not in it .