Though he rose and moved away, Reade, despite the darkness of the night, was careful to keep himself concealed behind the bushes, so that he could not be observed from beach or water. Shortly the young engineer was over at the point in the jungle from which he had seen the negro emerge with scow and explosives. "The fellow must use a magneto, attached to wires running under the water," concluded Tom. "At that rate, the first real job is to find the magneto. My, but Mr. Sambo Ebony may be wondering, to-night, why his blow-out doesn't work as easily as usual!" Simple as the search ought to have been, Tom Reade was soon on the point of despair. "If it isn't a magneto, or if I can't find it in time," Tom muttered uneasily, "the mystery may remain nearly as great as ever, and the explosion may be pulled off to-night, after all." Twenty minutes passed before Reade, with all his senses alert, stumbled on the concealed magneto. It had been so well hidden, under a mass of rocks, that it would not have been astonishing had Tom missed it altogether. Attached to the magneto was the wire that must connect, in some way, with the series of tubes that would soon be fastened in the retaining wall out yonder. Yet this wire ran into the ground, and then vanished. "Now, I've simply got to hustle!" sighed Tom Reade nervously. "If I don't succeed in raising the wire, and in a mighty short space of time, I may be to-night's fool yet. I'd really like to wish that on the black man, too!" By using his eyes and his reasoning powers Reade, after twenty minutes more of search, with some sly digging, unearthed a section of the wire some dozen feet from the magneto. "Now, it must be really the swiftest sort of work," murmured the young engineer, after a glance seaward. He seated himself with his face turned toward the Gulf, gathered the exposed section of wire up into his lap, then drew a pair of wire nippers from his pocket. Snip! Tom now had two ends of wire in his hands. That would have been enough, had Reade chosen to bury the ends and conceal all evidence of his work. However, he believed that a more workmanlike way could be found. From the same pocket Tom drew out a three inch piece of pure rubber cable, wrapped in water-proof tape. This he fastened to the severed ends of the wire, binding the whole as neatly as a lineman could have done. "Rubber is believed to be a pretty good insulator," chuckled Reade, as he finished. "I don't believe the spark is made that can jump three inches of rubber. Certainly magneto-power can't do it. Now, let me see what sort of a trail-concealer I am." Tom laid the wire back in the ground, covering it carefully with his hands. "I wish I dared strike a match, so that I could judge better just how my work looks," he sighed. "However, I don't believe Mr. Sambo Ebony will think it discreet to strike any matches either, so he won't find the place where I've been fooling with his work.