three o'clock
Meanwhile Ralph Mainwaring loudly lamented the missing jewels , until it was evident to all that their loss , for the time at least , had completely overshadowed all thought of the tragedy they were investigating . `` They must be recovered at all hazards and at any price , '' he said , addressing the detective . `` There were single gems in that collection which cost a fortune and which have been heirlooms in the family for generations . '' After further search which failed to disclose anything of importance , or any clue regarding either the murder or the robbery , arrangements were made for the inquest to be held at three o'clock that afternoon , and the party was about to leave the apartments , when Mr. Whitney paused . `` One moment , gentlemen ; there is one more point I would like investigated . I maintain that we have not yet discovered the most essential clue to this case -- something to throw light on the possible motive which prompted the murder of Hugh Mainwaring . I now wish to make a final trial .