"With my men patrolling the sea wall he must have to dive, some distance away, swim under water, and remain there until he has secured one of the tubes in place.

Then he has to get back, out of range of the lanterns' rays, and get his breath before he goes back to the next job.

But maybe I can interfere with his work to-night." 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.