Keeping his lips tightly compressed, the Sub, bending as he made his way through the fumes, dragged his companion back along the passage. He felt like a man who has dived too deeply. He wanted to fill his lungs with air, yet he knew that to attempt to do so might certainly end in disaster. The midshipman's inert body, which at first seemed hardly any weight to drag, now began to feel as heavy as lead. Once or twice the Sub stumbled, the effort causing his lungs to strain almost to bursting-point. It required all his self-control to prevent himself relinquishing his burden and jumping to refill his lungs with air which was so heavily charged with noxious fumes. At length he reached the canvas screen, that, having been soaked in water by the Turkish ammunition party, was still moist. With a final effort he thrust the curtain aside and took in a deep draught of air. It was comparatively fresh. The poisonous gases had failed to penetrate the close-grained fabric. Then, overcome by the reaction, Dick stumbled and fell across the body of his companion. How long he lay unconscious he knew not, but at length he was aroused by Sefton vigorously working away at the exercises for restoring to life those apparently drowned. Half-stupefied, the Sub resented. He was under the vague impression that he was in the gun-room of the _Hammerer_ and that the midshipmen were playing some practical joke. Then he began to realize his surroundings. The torch was still alight, but already the charge showed signs of "running down". The air, although close, was not heavily impregnated with fumes. No sound penetrated the rock-hewn vault. "Buck up, sir!" exclaimed Sefton with a familiarity engendered by the sense of danger. "We'll have to get out of this hole as soon as we can. Are you feeling fit to make a move?" Dick sat up. His head was swimming. His limbs felt numbed. He wondered why he had been in an unconscious state longer than his companion, until he remembered that throughout that terrible journey along the gas-charged passage Sefton had been dragged with his head close to the ground. Consequently, owing to the fumes being lighter than the air, he was not so badly affected. For another reason: when Dick collapsed, his weight falling across Sefton's body had acted very efficiently in expelling the bad air from the midshipman's lungs, and as the Sub rolled over the subsequent release of pressure had allowed a reflux of comparatively pure air to take the place of that pumped out of Sefton's chest. "Can't hear any firing," remarked Sefton. "I suppose our fellows have beaten them off."