[Footnote B: They came to him while he was asleep, and pressed him down with heavy feather beds, which they cast upon him to stifle his cries, and then thrust a red-hot spit up into his bowels through a horn, as some said, or a part of the tube of a trumpet, according to others, so as to kill him by the internal burning without making any outward mark of the fire on his person. Notwithstanding their efforts to stifle his cries, he struggled so desperately in his agony as partly to break loose from them, and thus made his shrieks and outcries heard.] [Illustration: BERKELEY CASTLE.] After this, Mortimer and the queen for two or three years held pretty nearly supreme power in the realm, though, of course, they governed in the name of the young king, who was yet only fourteen or fifteen years of age. There was, however, a great secret hatred of Mortimer among all the old nobility of the realm. This ill-will ripened at last into open hostility. A conspiracy was formed to destroy Mortimer, and to depose the queen-mother from her power, and to place young Edward in possession of the kingdom. Mortimer discovered what was going on, and he went for safety, with Edward and the queen, to the castle of Nottingham, where he shut himself up, and placed a strong guard at the gates and on the walls. This castle of Nottingham was situated upon a hill, on the side of which was a range of excavations which had been made in a chalky stone by some sort of quarrying. There was a subterranean passage from the interior of one of these caves which led to the castle. The castle itself was strongly guarded, and every night Isabel required the warden, on locking the gates, to bring the keys to her, and she kept them by her bedside. The governor of the castle, however, made an agreement with Lord Montacute, who was the leader in the conspiracy against Mortimer, to admit him to the castle at night through the subterranean passage. It seems that Mortimer and the queen did not know of the existence of this communication. They did not even know about the caves, for the mouths of them were at that time concealed by rubbish and brambles. [Illustration: CAVES IN THE HILL-SIDE AT NOTTINGHAM CASTLE.]