In vain did the battering-rams exert all their force against the walls, for they were extremely solid; in vain were ladders brought up in order to take the castle by assault, for the battlements were crowded with crossbow-men who rained down their arrows on all who approached the walls. Three times had the Cid taken up the standard of Castile and Leon, as at the escalade of Cea, and had endeavoured to mount the wall; but each time he had to fall back, seeing those about him killed, and himself preserved almost miraculously.
It was past midnight. Don Fernando had ordered the assault to be suspended, in order that he might deliberate with his captains, and particularly with the Cid, as to the precautions that should be taken in order to prevent the sacrifice of so many men-at-arms, and as to the best means for bringing the enterprise to a successful issue. They had demanded from its defenders the surrender of the stronghold, threatening that all would be put to the sword if they did not deliver themselves up by a certain day. That day had arrived, and the besieged still continued to defend it.
A Moor who was one of the sentinels on the battlements let himself down on the outer side of the wall, and, making his way to the royal tent of Don Fernando, asked to be brought into his presence. He was carefully examined, lest he might have concealed weapons, wherewith to commit some act of treachery, and, none having been found, he was brought before the king.
"Sire," he said to Don Fernando, "I believe it is your intention to take this place by storm and put all the inhabitants to the sword; I have a wife and children, whom I love, and in order to save them I have become a traitor to my faith and to my brothers-in-arms. Many years ago an arrow was shot from these very walls, which killed Don Alfonso, King of Leon, and the father of your queen; he who shot that arrow is now in Viseo. If you give me your word to spare my wife, my children, and myself, I will tell you who"—
"Glorious St. Isadore!" exclaimed Don Fernando, "what do I hear? Can it be possible that the murderer of the good Don Alfonso—for whom Queen Sancha still weeps—yet lives? Tell me who the traitor is, tell me his name, and I promise you, not only to spare yourself and your family, but also to load you with riches."
"Sire," hastened to answer the Moor, filled with joy, "he is named Ben-Amet, and is now charged with the defence of the wall of the Mosque; for, as it is it, above all, that should not fall into your hands, they have confided its defence to him."
"You are now at liberty either to remain here or to return into the town," said Don Fernando. "To-morrow we shall enter Viseo; whether you now go or remain with us, describe the position of your house accurately, and both it and its occupants shall be respected."
"Opposite the great Mosque there is a detached building with a handsome frontage; that is my house, sire, and my wife and children are in it."
The Moor retired to a tent, near that of the king, for he did not dare to return to the town. Shortly afterwards, Don Fernando summoned his captains and related to them what he had heard.
"We must," said the Cid, "make the assault at daybreak on the wall which that traitor defends, and all of us shall either take it or die in the attempt."