On and on he glided. The light of cooking fires faded. Laughter died away. Still he glided on. Then, of a sudden, he became conscious of a new sound—a throbbing that, beating faintly against his eardrums, seemed to come from nowhere. At first he thought it was the beating of his own heart and wondered at his increased power to hear in that silence. Soon enough he knew it was not that.
“But what is it?” he asked himself as he held his dripping paddle in mid-air to listen.
Getting no satisfactory answer, he drove his paddle into the water and sent his boat forward at renewed speed. This lasted for ten minutes. Perspiration ran down his cheeks as he paused to listen.
“Yes, yes, there it is, louder!” he murmured. “Much louder. It’s up the river. It’s a gasoline motor—a motor-boat. No, it can’t be.”
Dropping his paddle straight down, he touched bottom at eighteen inches. In such a stream there were sunken logs. No motor-boat could ascend to the spot where the motor was throbbing.
Swinging his boat about, he drove its prow against the shelving bank. Leaping ashore, he bent over, and putting his ear to the ground, listened.
“It can’t be,” he muttered, “and yet it is! It’s a stationary gasoline engine going full swing up that creek. And what’s more”—his thoughts were working rapidly now—“this creek runs up into our property. That engine is on our land. What can they be doing there?”
Creeping back into his canoe he allowed it to drift downstream. He wanted to go up and investigate, but it was too late. What that engine could be doing up there he could not so much as guess.
“But I’ll find out,” he told himself stoutly. “Leave it to me!”
Aside from slight damage done by a band of wild pigs, who in their search for food had rooted their way into the cook shack, the camp up the Rio Hondo was just as the boys had left it.
“It’s quite evident,” said Pant with a grin, “that Daego, or whoever it was that brought our work here to an end, thought there was time enough to come over and take possession.”
“Didn’t expect us back, that’s sure,” said Johnny.
They went to work with a will. Two days’ time saw a bigger and better camp erected, new roads cut into the jungle and everything in readiness for operation.