Notwithstanding the enforced calm that filled his soul, there were moments when, assailed by a terrible dread, lest he might be too late to prevent the unspeakable crime, his energies were almost paralyzed. Silent as a ghost he had traversed the grove by the side of his equally silent companions, more intent upon his quarry than the patient, velvet-footed puma that follows in the high branches of the trees the unsuspecting traveller below. Was it his imagination, was it the beating of his own heart in the silence that preceded the breaking of the storm; or did he indeed hear the dull throbbing of the drums that heralded the approach of the crimson banners of Satan? The wind increased with every moment. The thunder growled ever nearer. The heavens were one sheet of flame. The trees began to bend their tops to the voice of the hurricane. The air was hot as if blown from the depths of the desert. As the uproar of the elements increased, strange sounds seemed to mingle with the voices of the storm. Black shadows as of dancing witches darkened the clearing, spread and wheeled, interlaced and disentwined. In endless thousands they seemed to fly, like the withered and perishing leaves of autumn. Involuntarily Tristan grasped the arm of the Monk of Cluny. "Are these real shapes--or do my eyes play me false?" he faltered, an expression of terror on his countenance, such as no consideration of earthly danger could have evoked. "To-night, my son, we are invincible," replied the monk. "Trust in the Crucified Christ!" Across the plaisaunce, washed white by the sheen of the lightnings, there was a stir as of an approaching forest. Tristan watched as in the throes of a dream. A few moments later the little band was joined by the newcomers, masked, garbed in sombre black and heavily armed, three-score Spaniards, trusted above their companions for their loyalty and allegiance to Holy Church. Among them Tristan recognized the Cardinal-Archbishop of Ravenna, the Bishop of Orvieto and the Prefect of Rome. Odo of Cluny noted Tristan's shrinking at the sight of the two men who had been present when the terrible accusation had been hurled against him on that fatal morning--the accusation in the Lateran, which had launched him in the dungeons of Castel San Angelo. He comforted the trembling youth. "They know now that the charge was false," he said. "To-night we shall conquer. We shall set our foot upon Satan's neck." Withdrawing under the shelter of the trees, regardless of the increasing fury of the storm, the leaders held whispered consultation. Before them, set in the massive wall, appeared a door not more than five feet high, studded with large nails.