Outside the camp the two other men-at-arms were waiting for them, and the four advanced together. Presently a little group of figures loomed up in the darkness. It was a cloudy night, and a thin rain was falling which obscured both the castle and the fort; but a stone had been placed by Simon in the daytime which assured that they were between the two.
"Is blind Andreas there?" asked Simon.
"Yes, kind sir, I am here," said a voice.
"This man," said Simon, "was once rich and of good repute, but he was beggared by this robber lord, who afterwards put out his eyes so that he has lived for many years in darkness at the charity of others."
"How can he help us in our enterprise if he be indeed blind?" asked Nigel.
"It is for that very reason, fair lord, that he can be of greater service than any other man," Simon answered; "for it often happens that when a man has lost a sense the good God will strengthen those that remain. Hence it is that Andreas has such ears that he can hear the sap in the trees or the cheep of the mouse in its burrow. He has come to help us to find the tunnel."
"And I have found it," said the blind man proudly. "Here I have placed my staff upon the line of it. Twice as I lay there with my ear to the ground I have heard footsteps pass beneath me."
"I trust you make no mistake, old man," said Nigel.
For answer the blind man raised his staff and smote twice upon the ground, once to the right and once to the left. The one gave a dull thud, the other a hollow boom.
"Can you not hear that?" he asked. "Will you ask me now if I make a mistake?"
"Indeed, we are much beholden to you!" cried Nigel. "Let the peasants dig then, and as silently as they may. Do you keep your ear upon the ground, Andreas, so that if anyone pass beneath us we shall be warned."
So, amid the driving rain, the little group toiled in the darkness. The blind man lay silent, flat upon his face, and twice they heard his warning hiss and stopped their work, whilst some one passed beneath. In an hour they had dug down to a stone arch which was clearly the outer side of the tunnel roof. Here was a sad obstacle, for it might take long to loosen a stone, and if their work was not done by the break of day then their enterprise was indeed hopeless. They loosened the mortar with a dagger, and at last dislodged one small stone which enabled them to get at the others. Presently a dark hole blacker than the night around them yawned at their feet, and their swords could touch no bottom to it. They had opened the tunnel.