Try as he would, the Boy could not wrench himself free of the slough. The water, as he stood upright, was on a level with his mouth. The air-hole was too wide for him, at such a depth, to get a good purchase on its edges and lift himself bodily to safety. Gaining such a finger-hold as he could, he heaved with all his might, throwing every muscle of his body into the struggle. One leg was pulled almost free of the mud, but the other was driven deeper into it. And, as the Boy’s fingers slipped from the smoothly wet ice-edge, the attempt to restore his balance drove the free leg back, knee-deep into the mire. Ten minutes of this hopeless fighting left the Boy panting and tired out. The icy water was numbing his nerves and chilling his blood into torpidity. His hands were without sense of feeling, as far up as the wrists. Even if he could have shaken free his legs from the mud, now, he had not strength enough left to crawl out of the hole. He ceased his useless frantic battle and stood dazed. Then he came sharply to himself. For, as he stood, the water crept upward from his lips to his nostrils. He knew why the water seemed to be rising. It was not rising. It was he who was sinking. As soon as he stopped moving, the mud began, very slowly, but very steadily, to suck him downward. This was not a quicksand, but it was a deep mud-bed. And only by constant motion could he avoid sinking farther and farther down into it. He had less than two inches to spare, at best, before the water should fill his nostrils; less than two inches of life, even if he could keep the water down to the level of his lips. There was a moment of utter panic. Then the Boy’s brain cleared. His only hope was to keep on fighting—to rest when he must, for a moment or so, and then to renew his numbed grip on the ice-edge and try to pull his feet a few inches higher out of the mud. He must do this as long as his chilled body could be scourged into obeying his will. He struggled again, but with virtually no result in raising himself. A second struggle, however, brought him chin-high above the water. He remembered confusedly that some of these earlier struggles had scarce budged him, while others had gained him two or three inches. Vaguely, he wondered why. Then turning his head, he realised. Wolf, as he turned, was just loosing his hold on the wide collar of the Boy’s mackinaw. His cut forepaws were still braced against a flaw of ragged ice on the air-hole’s edge, and all his tawny body was tense. His body was dripping wet, too. The Boy noted that; and he realised that the repeated effort to draw his master to safety must have resulted, at least once, in pulling the dog down into the water with the floundering Boy. “Once more, Wolfie! _Once more!_” chattered the Boy through teeth that clicked together like castanets.