"Yes, we've come a good way," replied Dummy, "and you didn't have no sleep last night." The boy munched his last crust, and then lay flat down on his breast, with his mouth over the pool, lowered his lips, and took a long deep drink, after the fashion of a horse. After this, he rolled himself clear away, and lay upon his back, staring at the two candles stuck in the crack a few feet above his head. "Does rest your back and lynes, Master Mark, to lie like this for a bit. You just try it." There was no reply. "D'you hear, Master Mark? You try it." Still no response, and he turned his head, to see that his companion's chin was resting upon his chest. "Sleep!" said Dummy, with a little laugh. "Can't stand being up all night like I can. Being on night-shifts, sometimes, I s'pose. Well, let him sleep for a few minutes, and then I'll wake him." Then all was blank. CHAPTER TWENTY THREE. JUST IN TIME. All at once Dummy Rugg uttered a peculiar snort, and started up in a sitting position, with the thought still fresh in his brain that he must rouse up Mark from his nap. But all was dark, and there was the gurgling rush of the water below. "Why, I've been asleep," muttered the lad excitedly. "Think o' me doing that!" He rose quickly, and felt for the crack in which he had stuck the candles, narrowly escaping a plunge into the little pool from which he had drunk. He found the spot where the candles had been, both of them; he could feel it by the size, and knew it by the shape, for it grew smaller at each extremity, so that he had been able to wedge the ends of the candles tight. Yes: there was no doubt about it. Both candles, as if to be in fashion with the stony drippings of the cavern, had run down a little, to form tiny stalagmites of grease. "Burnt right out," muttered Dummy, still more excitedly. "Why, I may ha' been asleep for hours." Thrusting his hand into his breast, there was a faint rattle as he drew out tinder-box and match, and then felt for a candle in the box he had carried slung by a strap from the shoulder, and laid it ready. The next minute he was nicking a piece of flint against the steel, striking sparks down into the box, and at the second sharp click Mark started awake. "Yes! What is it?" he cried--"Where am I?" "On'y here, Master Mark," replied the boy. "Candle's gone out." "Why, Dummy! Have we been to sleep?" "I s'pose so, Master Mark. Po-o-o-o-f-f-uf! There we are!" He had obtained a light, the match burning up brightly, and then the candle, after the fluffy wick had been burnt and blown. "How tiresome! I don't know, though. I feel rested." "Being up all last night, I s'pose," said Dummy, as he stuck the candle in the crack. "Yes, of course; that's it. Think we've been asleep long?" "I dunno. Fear'd so." "Let's go back, then, at once," said Mark, springing to his feet. "Why, we may have been asleep for hours. Light another candle, and let's get back."