midnight
Content with having destroyed the door , the assailants made no further effort that evening , but prepared in the morning to attack it , pull down the stones filled behind it , and force their way into the keep . There was , with the exception of the main entrance , but one means of exit , a small postern door behind the castle , and throughout the siege a strong body of troops had been posted here , to prevent the garrison making a sortie . Feeling secure therefore that upon the following day his enemies would fall into his power , Sir Rudolph retired to rest . An hour before midnight the garrison assembled in the hall . The table was removed , and Cuthbert having pressed the spring , which was at a distance from the stone and could not be discovered without a knowledge of its existence , the stone turned aside by means of a counterpoise , and a flight of steps was seen . Torches had been prepared . Cnut and a chosen band went first ; Cuthbert followed , with Lady Margaret and her attendants ; and the rest of the archers brought up the rear , a trusty man being left in charge at last with orders to swing back the stone into its place , having first hauled the table over the spot , so that their means of escape should be unknown .