The darkness, unrelieved by even the light of moon or stars, hid everything within a cloak of invisibility, so that even the castle itself was but a blur, revealed only by flickering gleams of illumination from a few windows. That, and one other thing. On top of the castle itself three men, working by the light of four or five lanterns, moved busily about to the accompaniment of hammering. They were erecting the gallows from which Imre was shortly to hang. Wenzel cursed at the sudden, unforeseen obstacle in the fulfilment of his plans. "Hell! May the Devil seize him! Do you think Comrade Grocz suspected he was being followed, Arnold?" "No, I think not," Terhune replied slowly. "Then why the order not to let in even Bela Kun himself?" Arnold shrugged his shoulders. "A sense of authority in the first place, but there is a worse aspect. After the hanging Grocz wishes no interruption in his filthy schemes." Wenzel's muscles tightened. "God grant me the chance to grip his soft throat between my thumbs," he muttered between his teeth. "But now, is there another way in? Let us explore, Arnold." Stumbling along the uneven rocky surface, Wenzel and his lieutenant proceeded to examine, as far as possible, the geography of the castle. Keeping well beneath the shadow of the outer battlements they knew they were safe from the observation of those within the castle. It would be only Communists or sentries actually above them on the battlements who would be likely to hear or see them--an unlikely contingency. Presently they came to one corner; here the wall turned off at right angles to make a second side of the square in which the castle was built. Continuing, the two Englishmen turned also. For perhaps two hundred feet they crept along without discovering any sign of another door. Suddenly Wenzel stopped, restraining Arnold by a touch on his arm, his keen ears having become aware of a strange, sighing echo, a noise hollowly flung at them from out of the darkness. He felt the influence of a cold wind, a sensation of space. He looked ahead, then beneath him, and gasped slightly. Deep down below, an inestimable distance, were lights eerily waving to and fro. Another few steps and they might have hurtled into the depths before them. The lights puzzled him; he could make nothing definite of their fantastic action. What, too, was the soughing below? All at once the solution occurred to him. The lights below were reflections of others above. "The Danube!" he breathed softly. "Good Lord!" Arnold was horrified. "Another few steps and----" "Perhaps." That was all! Coolly indifferent to the possibility of having just escaped death, the White Knight passed again to the front of Arnold and they retraced their steps. They reached the gates again, and with the utmost caution passed by in front of them, then explored the other side of the castle.