He went to bed. But he did not sleep. Those singular pyramids and the cipher still lingered before his inner vision. What was the mystery hidden behind the dead man chained in the rotting barque, the headless skeletons lying near the swamp, and now these documents, found in the tube and so carefully concealed? "I give it up," he told himself at last, in an effort to dismiss it all and compose his active brain. "I wish I had a stouter tube to make a good bomb for the tiger." He thought perhaps he could use the oxidized cylinder as it was, and began thereupon to wonder how he should make a fuse by which its powder contents might be ignited. Thus he drowsed off at last, with fantastic dreams swiftly solving the sum of his problems. CHAPTER XII AMBITIOUS PLANS Grenville awoke with a brilliant idea, born in his brain as he slept. It was not concerned with the documents found in the old brass receptacle, but entirely with the tiger. He knew how to fashion a fuse. The creepers had answered this latest need, with their bark so readily hollowed. He had burned up yards of the drying stuff with the core removed, all of it shrunk and twisted tight, like long coils of vegetable tubing. He had only to fill it with his powder while green, and then let it dry in the sun. He could likewise fill the useless cylinder, wrap it about to increase its resistance to the powder--and thereby render its explosion far more violent. If, after that, a chance were presented to ignite it under the tiger---- It was possible always, he confessed, the tiger might prove unwilling. However, both the cannon and bomb should be immediately prepared. There could be no peace upon the island while the brute remained alive. All thoughts of the cipher were postponed for evening recreation. The day's work began after breakfast in preparing large quantities of powder. At this Elaine assisted. She was glad of any employment. No less in her veins than in Grenville's the promptings of being in the primitive were daily surging stronger. Like himself, she was hungry for meat; and while she had no thoughts of turning Amazon herself, she felt an increasing interest in all that Grenville was attempting in his task of coping with nature. Meanwhile Sidney was daily assuming a wild and unkempt aspect that he could not possibly avoid. His beard was an unbecoming stubble that he was powerless to shave; his hair was uncombed and a trifle long; his clothing was not without its rents. But what an active, muscular being he appeared, as he moved about at his work! He seemed so thoroughly fearless, so competent and at home with naked Nature. His thoughtfulness, moreover, had no limits, and neither had his cheer. He had made no further disquieting advances, but seemed rather to have forgotten, utterly, the lawless emotions to which he had one day given way.