After a search of two hours, Cnut decided that the only place in the copse in which it was likely that the entrance to a passage could be hidden, was a spot where the ground was covered thickly with ivy and trailing plants.

“It looks level enough with the rest,” Cuthbert said.

“Ay, lad, but we know not what lies behind this thick screen of ivy.  Thrust in that staff.”

One of the woodmen began to probe with the end of a staff among the ivy.  For some time he was met by the solid ground, but presently the butt of the staff went through suddenly, pitching him on his head, amidst a suppressed laugh from his comrades.

“Here it is, if anywhere,” said Cnut, and with their billhooks they at once began to clear away the thickly grown creepers.

Five minutes’ work was sufficient to show a narrow cut, some two feet wide, in the hill side, at the end of which stood a low door.

“Here it is,” said Cnut, with triumph, “and the castle is ours.  Thanks, Cuthbert, for your thought and intelligence.  It has not been used lately, that is clear,” he went on.  “These creepers have not been moved for years.  Shall we go and tell the earl of our discovery?  What think you, Cuthbert?”

“I think we had better not,” Cuthbert said.  “We might not succeed in getting in, as the passage may have fallen farther along; but I will speak to him and tell him that we have something on hand which may alter his dispositions for fighting to-morrow.”

Cuthbert made his way to the earl, who had taken possession of a small cottage a short distance from the castle.

“What can I do for you?” Sir Walter said.

“I want to ask you, sir, not to attack the castle to-morrow until you see a white flag waved from the keep.”

“But how on earth is a white flag to be raised from the keep?”

“It may be,” Cuthbert said, “that I have some friends inside who will be able to make a diversion in our favour.  However sir, it can do no harm if you will wait till then, and may save many lives.  At what hour do you mean to attack?”

“The bridges and all other preparations to assist us across the moat will be ready to-night.  We will advance then under cover of darkness, and as soon after dawn as may be attack in earnest.”

“Very well, sir,” Cuthbert said.  “I trust that within five minutes after your bugle has sounded, the white flag will make its appearance on the keep, but it cannot do so until after you have commenced an attack, or at least a pretence of an attack.”

Two or three hours before daylight Cuthbert accompanied Cnut and twenty-five picked men of the foresters to the copse.  They were provided with crowbars, and all carried heavy axes.  The door was soon prised open.  It opened silently and without a creak.