Then he swung himself up to the roof of the dormer window and proceeded to haul himself by the rope up the steep incline, helping himself as much as possible with his feet and knees. He was heartily glad when he gained the ridge, and had thus accomplished the most dangerous part of the work. He was able now to fix the grapnel firmly, and sitting astride of the roof, he called down that he was ready. It was easier work for Albert to follow him. Not only was the latter certain that the grapnel was safely fixed, but Edgar, pulling upon the rope, was enabled to give him a good deal of assistance. In two or three minutes Hal Carter joined them. "In faith, master," he said, panting, "I had not deemed that so much of my strength had gone from me. If it had not been for the help you gave me I doubt if I could have climbed up that rope." They now made their way along to the end of the roof. The grapnel was fixed, and Edgar slid down the rope to the next roof, which was some fifteen feet below them. They did not attempt to free the grapnel, fearing that in its fall it might make a clatter; they therefore used another to mount to the next house, which was as high as that which they had left. There was but a difference of four feet in the height of the next, and they had not to use the grapnel again until they reached the sixth house, which was ten feet below that next to it. [Illustration: THE PRISONERS MAKE THEIR ESCAPE OVER THE ROOFS OF YPRES.] There was light enough to enable them to make out the position of the dormer window below them, and fixing the grapnel, Edgar, aided by his companions lowering him, made his way down beside it, and knelt upon the sill, his companions keeping a steady strain upon the rope. With his chisel he had but little difficulty in prising open the casement. His companions were not long in joining him. Once inside the house they made their way with great caution. They had no means of striking a light, and were forced to grope about with their swords in front of them to prevent their touching any piece of furniture, till at last they discovered the door. It was not fastened, and passing through, and, as before, feeling the floor carefully as they went, they presently found the head of the stairs. After this it was comparatively easy work, though a stoppage was necessary at each landing. At last, to their satisfaction, they found themselves in a flagged passage, and knew that they were on the ground floor. They made their way along the passage, and soon reached the door. It was locked with so massive a fastening that it would have been difficult to unfasten it from the outside; but with the aid of the chisel they had but little difficulty in forcing back the lock. They paused for a minute to listen, as a passer-by might have been startled by the sound of the bolts being shot in an empty house. All was quiet, however, and, opening the door cautiously, Edgar stepped out.