midnight
I shall remain in the chamber underneath . `` But you two ought to show yourselves immediately after sundown . Certain ancient writings indicate it . You , and the Nervina , will have to mount the stair to the Spot , and remain in sight until midnight -- until the end . `` So we must be prepared for accidents . '' He took some papers from his pocket , and selected two , and gave one to each of his pupils . `` Here are the details of what must be done .