In the tiger's lair

Ted’s first impulse was to tell Stanley immediately of the conversation he had heard in the hangar. But the roar of the motor made this impossible. Then it occurred to him that the two officers might be watching them, so he decided to withhold the information until they were safely in their own quarters.

Stanley’s face was a puzzle as he listened to the story. He did not interrupt until the recital was completed.

“I am surprised that they should resent our presence here,” he said finally. “There is room enough for all of us, but these fellows must have come bent on being the whole show and are determined to have their way. Still, it is almost impossible to believe they were altogether in earnest. Perhaps they knew you were listening and tried to frighten us.”

“That is what they said, no matter what their real intention. I think the thing ought to be reported to the colonel.”

“Perhaps we should report it, but that would only make matters worse. Why not wait until we have some proof of their intentions? Then we shall have a fair case against them. In the meantime I guess we can take care of ourselves.”

“We must take every precaution. There is too much at stake for us to make a break one way or the other.”

“Yes, we will be very careful. And we will let it go at that. I think we shall be able to tell without trouble if there has been any tampering with the ships. A strict watch must be kept, for one thing, and we shall make a most thorough inspection of our machine before each flight,” said Stanley. “Above all, we must work fast; that is, get into and out of our destination as soon as possible, and then we shall be at liberty to leave the country. If we speed up we may be able to forestall our rivals.”

“How about a test flight to-morrow? And then an attempt to reach the hidden place a few days later?”

“The very thing. Have a first trial flight to-morrow and then spend a few days making adjustments while we also make our other preparations. After that the dash for the mountains. But we may have to alter our plans greatly. With the opposition and competition we have now it will not be possible to make an unlimited number of flights. We might succeed in going once or twice without trouble, but if we went too often and remained away for long periods of time they would become suspicious and either stop us or try to follow to see what we were doing.”

“I have a scheme we could try. Why not take a load of equipment on the first trip and cache it in one of the caves; then open up the underground river and take out as much gold as we want that way. If we have to discontinue flying before we bring out very much in the plane we can go back by the overland route and pick up what we have hidden in the forest. That will save a lot of time and trouble.”

“We could not improve on that if we tried,” Stanley agreed enthusiastically. “While I do the final tinkering on the machine you can be gathering the things together. Bring them to our hangar, load them at night, and we can hop away early the next morning.”

Somehow the news had spread that there was to be a trial flight on the following day, and a huge crowd, composed mostly of Indians, gathered on the outskirts of the field at daybreak. It was not until shortly after noon, however, that everything was in readiness for the initial attempt. The two donned their leather coats, helmets, and goggles, and climbed into the cockpits. At a signal from Stanley the crew removed the wooden blocks from under the wheels and swung the ship around into the wind. Stanley gradually opened the throttle, and as the roar of the engine increased in volume the machine gathered speed and raced over the even ground. In a moment it had left the earth and was soaring upward at an appreciable angle. The crowd of onlookers waved their hats and burst into a wild cheer, and Ted, who was standing in the rear pit, leaned over the rim and waved his hand toward the ground as they sped into the distance.

Stanley carefully watched the braces, struts, and wings, but as there was no unusual vibration, he tried a number of turns, banking gently, dived and zoomed, and in other ways tested the craft. Its stability and balance were to his entire satisfaction. Then they ascended to a height of five thousand feet and performed a series of stunts that even the birds would not dare attempt. They side-slipped, dived, and spiralled, did wing-overs, and ended in a series of loops. After that they descended to the field in a long tail-spin, levelling off just in time to land easily and gracefully in front of their hangar.

The colonel was most enthusiastic and congratulated them heartily, but the two lieutenants kept in the background and offered no comments.

“There are only a few wires to tighten a little,” Stanley informed the commanding officer. “They are always liable to slacken somewhat during the first flights. The fuselage is lined up perfectly. If the colonel so desires, we shall be glad to make a long cross-country flight next Sunday. That could serve as a final test, after which the ship would be ready to go into commission for the regular work of training cadets.”

“Splendid!” the colonel replied. “Go anywhere you like. Give the machine a most thorough trial. The instructors and pupils are waiting impatiently for their turn.”

Two days later, as they were going over the ship for a final inspection, Stanley suddenly noticed that the keys had been removed from the pins that fastened the right upper wing to the body. With a slight motion of his hand he indicated the fact to Ted.

“Now we shall find out who is responsible for that,” he said to Ted between his teeth.

They had the ship rolled out on the line and started the engines. The colonel and the two lieutenants were on the field as usual, watching the operations.

“Perhaps the lieutenants would like a flight to-day?” Stanley suggested pleasantly, approaching the trio. “With the colonel’s consent, and so far as we are concerned, the ship is at your disposal.”

The two began to look uncomfortable, and one of them stammered an excuse about not being prepared with the proper clothing. The colonel promptly suggested that they might use the outfits of the Americans if they desired, but upon this the other one pleaded illness.

“Well,” Stanley said, looking straight at the two, “we thought we might go up for a few minutes, but I guess we had better not. If it is not safe for you, it is not safe for us.”

The colonel understood that there was some difficulty, but said nothing until the two instructors had gone. Then he questioned the Americans as to the meaning of the affair. They showed him the pins with the missing keys.

“But you have no evidence against any one!” he said slowly. “This is most serious, but I cannot accuse any one of such an act without proof.”

“No, but in the future the hangars must be guarded day and night. No one must be permitted to enter without a written pass from you.”

“That is a good idea. It shall be done. I shall immediately issue an order to that effect.”

The damage was soon repaired and the ship rolled back into the hangar.

Ted spent the greater part of the next morning making purchases in the city, and the packages were delivered to the field early in the afternoon. They had been compelled to buy numerous things connected with their work during the previous weeks, so the arrival of the boxes caused no comment. Ted stored them in a corner of the hangar and covered them with a tarpauling.

That night they carefully studied their map, on which the location of the Hidden Valley had been marked as accurately as possible, as they had done so many times before. And at daybreak on the following morning Ted loaded the packages into the ship, while Stanley went for a conference with the colonel. When the latter, too, arrived on the field, the plane was on the line with the engine roaring.

Although the guards assured them that none had approached the hangar during the night, the two spent considerable time in a minute inspection of the machine. And when the sun was an hour high in the heavens they left the ground, circled the field until they had reached an altitude of several thousand feet, then headed straight to the north.

If their calculations were right, they should reach the valley in an hour, unless they encountered a strong head-wind. Allowing another hour for the return, there would be a leeway of a third hour, for the fuel-supply, counting that contained in the emergency-tank overhead, was ample for three hours.

From directly above, the mountain-peaks appeared flattened out exactly like the plateaux and valleys, but they could be distinguished from the latter by the patches of snow and fields of black rocks. A wind from the south added greatly to their speed, so that the landscape beneath them moved back at a rapid pace. To their right, and far, far below, lay the sea of dark-green Amazonian jungle.

Here and there among the bleak mountain-peaks lay little green valleys with square, blocklike dots scattered about singly and in groups. To the casual observer they might have been mistaken for stones. But to the trained eye they were clearly Indian huts, distinguishable from the other objects by their regular outlines. And if Ted looked closely he could make out minute specks moving toward the houses; they were the Indians running to shelter, terrified, no doubt, by the roaring spectre in the sky.

“Keep your eyes open wide,” Stanley shouted back to his companion after he had throttled down the motor so that its roar did not drown the sound of his voice. “Look for the yellow vapor and the ring of volcanoes. The wall, too. What was that?”

A black form had passed them at great speed, its shadow blanketing one side of the craft.

Ted looked back, knowing that it could not have been a cloud, for the sky was clear.

“It’s a condor,” he called at the top of his voice, just as Stanley opened the throttle. Even as he spoke the great bird was wheeling gracefully and heading in their direction. Master of the desolate mountain tops and of the air above them, the huge bird was evidently investigating or challenging this newcomer into its realm.

Ted pounded the linen side of the fuselage frantically with his gloved hand, and at the signal Stanley automatically pushed the control forward, ever so slightly, and the ship went into a steep dive. It was part of their old code, originated on the Western Front, and in the emergency both remembered it instantly.

They were not a moment too soon. The great bird shot past above them with a rush of wings audible above the slow throbbing of the throttled-down motor.

Just as Stanley brought the plane to a level keel, the bird wheeled, and again came toward them, from the front, but this time the pilot saw it in time. He must avoid collision with the audacious creature, for the impact of the heavy body against the struts of propeller would be enough to shatter them and send them crashing to the ground. His first impulse was to use the machine-gun in an attempt either to kill the bird or to cause it to swerve; but a second thought seemed better. He waited until the black form was a scant hundred yards away; then he pulled hard on the control, and instantly the bird seemed to drop into space below them. What had really happened was that the ship had bounded upward in a steep zoom, passing high above the attacker, and before the latter could turn, Stanley had resumed the level course and opened wide the throttle. The ship started forward at such great speed that the bird, swift of wing though it was, could not overtake them; and they soon lost it in the distance, a black speck growing constantly smaller in the unclouded sky.

After that they flew at a lower altitude, so as not to arouse the ire of other condors that might be soaring at that dizzy height.

Ted was carefully scanning the ground, on which everything now appeared with startling distinctness. Below was an Indian trail on which a caravan of llamas had been wending its leisurely way. The leader of the file stopped and evidently sounded an alarm of some kind, for in a moment the panic-stricken animals were dashing down the trail, leaving a cloud of dust in their wake and scattering their packs by the wayside. After leaping a stone wall they disappeared into the doorway of a hut. At the same time a number of Indians, wearing bright-colored blankets, darted out of the rear doorway, routed from their abode by the onrushing beasts, but no sooner had they gained the open than one of the group discerned the strange monster above them, and back they dashed into the hut.

Ted was watching the spot long after to see if any of the occupants of the shelter would appear after they had passed, when the engine again slowed down.

“That looks like the spot over there,” Stanley shouted, nodding toward the landscape in front of them.

Ted looked in that direction and nodded assent. Far ahead, and to one side, lay a circle of yellow vapor; it seemed to hug the earth in a solid ring, while columns and whisps rose into the sky to a great height. That could mean but one thing. It was the impenetrable barrier of poisonous gases arising from the chain of volcanoes surrounding the Hidden Valley. A quarter of an hour later they had crossed the margin of the ring. There it was, directly beneath them—the long valley with its winding river, Uti with the dismal lagoon glistening in the sunlight, and the great wall that separated the two places showing like a narrow gray ribbon. To the left was another valley with high, steep walls of rock hemming it in on all sides, but there was no vapor clinging to the rim of that enclosure.

Stanley shut down the power and they began a rapid and almost noiseless descent in a series of graceful spirals. When down to five hundred feet above the ground, he again opened the throttle and circled a few times, while both craned their heads over the sides of the cockpits, looking for a suitable place to land. In a moment they recognized the level strip of beach on the border of the lake, the very spot, in fact, where their canoe had been stranded several years before; another spiral, then a long glide, and they had landed on the hard sand.

At last they were in the region of gold-filled caves, a mere stone’s throw from the place where the vast treasure of the Incas had lain untouched for so many centuries. The two scrambled out of their cramped quarters and jumped to the ground. Then, dashing their helmets and goggles aside, they started in a wild rush toward the cave.