a quarter to eight o'clock
`` It came by the last post , '' said he . `` Read it aloud . '' The note was undated , and without either signature or address . `` There will call upon you to-night , at a quarter to eight o'clock , '' it said , `` a gentleman who desires to consult you upon a matter of the very deepest moment . Your recent services to one of the royal houses of Europe have shown that you are one who may safely be trusted with matters which are of an importance which can hardly be exaggerated . This account of you we have from all quarters received . Be in your chamber , then , at that hour , and do not take it amiss if your visitor wears a mask . ''