ten o'clock
`` Of course , the two sentries must be first silenced . I would wait till I , myself , should be on sentry there ; but that might not occur for a week , and you can not prolong your stay here more than another day ; therefore , we will try it tonight . I have given the men with the horses notice . `` Do you get the priest bound and gagged , by ten o'clock ; everything will be quiet by that time . I will come noiselessly up the steps . At that hour , do you be at the door , and on the lookout for me . The sentries will have to be silenced -- that is the most difficult part of the business . ''