“I should be getting reports on the drones soon,” Tom thought eagerly. “I hope they’re encouraging.”
Two of the drones beeped on the first flight out. When the sites were checked later, one proved to be a low-grade iron ore deposit, the other of zinc. A third plane, which beeped the following day, failed to come back to base.
“It must have crashed, skipper,” George Dilling reported gloomily.
Tom studied the chart of its flight area in the communications shack. “Where, approximately, would the bird have been when it beeped?” he asked.
Billing fingered the spot on the map. He had already figured the position by computer.
“Okay, we’ll trace its whole flight course between there and camp,” Tom said.
He and Bud took off at once in a Whirling Duck. The drone had been flying a gridlike search pattern to the northeast. Hours went by with no A TERRIFIED CAMP 153
sight of the lost homing pigeon. Finally the boys found themselves over a secluded mountain valley.
“We must be coming close to the spot where -” Tom stopped speaking.
A sudden blast of ack-ack fire had thundered from the valley. “We’ve been hid” he cried.
CHAPTER XVII
THE AMIR’S MINE
THE attack on the helijet had come with such stunning suddenness that neither Tom nor Bud knew what to expect next.
But now Bud cried out, “Down there! Look!” A slim, deadly-looking antiaircraft gun was poking up from the brush-covered floor of the valley. It wheeled, keeping the muzzle trained on the helijet. But there was no further fire. The first burst had done its job.