"I wonder what spiflicating is?" mused Kettle, but he did not remain cudgelling his brain over this for long. It occurred to him that if this negro could come and go so handily to the outside of this underground prison, there must be a stairway somewhere near, and though he could not enlarge the slit to get at it that way, it might be possible to burrow a passage under the wall itself. For a tool, he had spied a broken crock lying on the floor, and with the idea once in his head, he was not long in putting it to practical effect. He squatted just underneath the slit, and began to quarry the earth at the foot of the wall with skill and determination. But if Kettle was prompt, his captors were by no means dilatory. Between Kettle's prison and the mate's was another of those bottle-shaped _oubliettes_, and in that there was presently a bustle of movement. There came the noises of some one lighting a fire, and coughing as he fanned smouldering embers into a glow with his breath, and then more coughing and some curses as the fire-lighter took his departure. The door above clapped down into place, and then there was the sound of someone dragging over that and over the doors of the other two prisons what seemed to be carpets, or heavy rugs. There was something mysterious in this manoeuvre at first, but the secret of it was not kept for long. An acrid smell stole out into the air, which thickened every minute in intensity. Kettle seemed dimly to recognize it, but could not put a name to it definitely. Besides, he was working with all his might at scraping away the earth from the foot of the wall, and had little leisure to think of other things. The heat was stifling, and the sweat dripped from him, but he toiled on with a savage glee at his success. The foundations had not been dug out; they were "floating" upon the earth surface; and the labor of undermining would, it appeared, be small. But Murray in the other prison had smelt the reek before, and was able to put a name to it promptly. "By Jove! Captain," he shouted mistily from the distance, "they're going to smoke us to death; that's the game." "Looks like trying it," panted the little sailor, from his work. "That's dried camel's dung they're burning. There's no wood in Arabia here, and that's their only fuel. When the smoke gets into your lungs, it just tears you all to bits. I say, Skipper, can't you come to some agreement with Rad over those blessed rifles? It's a beastly death to die, this." "You aren't dead--by a long chalk--yet. More'm I. I'd hate to be--smoke-dried like a ham--as bad as any Jew. But I don't start in--to scoff the cargo--on my own ship--at any bally price." There was a sound of distant coughing, and then the misty question: "What are you working at?" "Taking--exercise," Kettle gasped, and after that, communication between the two was limited to incessant staccato coughs.