As they climbed the wall a large stone was displaced and went rolling and bounding down the hill side. Then, just as they jumped to the ground, there was a sudden puff of wind and the cloud of fog rolled away, almost as if it were a great white blanket withdrawn by invisible hands. And there on the tor above them Rupert saw clearly outlined against the sky two horsemen, about three hundred yards apart. "By God, we’re done!" 303 cried. The mounted warders raised a shout, and jabbing their heels into their ponies’ sides, commenced to gallop down the hill. "We must make a run for it," Rupert said. "There’s fog still in the valley." Before he finished speaking, 303 had torn off like a hare, leaping, stumbling, dashing first one way, then another to avoid obstacles. Rupert followed. Twice 303 fell, and each time Rupert waited to lend him a hand. Once he glanced back and he saw the warders reach the wall; they dismounted, and one commenced to pull the stones off the wall to make a gap for his pony; the other unslung his rifle and shouted to the flying convicts to stop—or he would fire. Twice the warning came. They were racing side by side now. Rupert heard himself laugh. The sheltering pall of fog was not a hundred yards away now. He set his teeth and flung back his head while he waited for the crack of the warders’ carbines and the "ping" of the buckshot. It came just as the kindly fog was about to envelop them again. Ten seconds more and they would have been safe. Perhaps the warder had the instincts of a sportsman. Perhaps he had purposely given them a run for their money. But he had to do his duty. He knew that if once they got into the fog again they would be lost. So he fired. He saw the right-hand man stumble, then roll over and over like a shot rabbit until he lay quite still face downwards on the heather. Before he could raise his carbine and fire again the other man had disappeared. Both warders let go their ponies, stumbled over the wall and ran down the hill-side to the fallen convict. The man who had fired the shot stooped down and turned him over. And he started and looked at his companion. The convict’s face was white as death; blood was flowing from a wound on his forehead. "My God Bill, you’ve done it this time!" the second warder said. "You’ve killed him!" CHAPTER XVII. AT POST BRIDGE HALL. The warders stared into each other’s faces. "It’s a bad job. You’re sure he’s dead——" "I wouldn’t have done it for anything," the man who had fired the shot whispered. "I aimed at his legs, too. Damn the gun!" He threw it into the heather, and turned away to hide his emotion. The second warder glanced back over his shoulder. The fog was slipping down the hillside again. The stone wall and the ponies were already lost to view. "Fire off your gun again; they’ll hear it on the road. I’d better go back for the ponies, or we shall lose ’em."