twelve o'clock
`` In the meantime the housekeeper had also arrived upon the scene , but she was just too late to catch the young man 's dying words . Leaving Susan with the body , she hurried to the Professor 's room . He was sitting up in bed horribly agitated , for he had heard enough to convince him that something terrible had occurred . Mrs. Marker is prepared to swear that the Professor was still in his night-clothes , and , indeed , it was impossible for him to dress without the help of Mortimer , whose orders were to come at twelve o'clock . The Professor declares that he heard the distant cry , but that he knows nothing more . He can give no explanation of the young man 's last words , ` The Professor -- it was she , ' but imagines that they were the outcome of delirium . He believes that Willoughby Smith had not an enemy in the world , and can give no reason for the crime .