nod he added, "Then maybe our friends just ducked into one of them temporarily, to cover their tracks, and will be coming out again soon."

Ken felt the letdown too. "If that's-" But he broke off because Ramon was speaking again.

"We will have to check the trails, nevertheless. This man knows his business"-he patted the shoulder beneath the faded serape-"but after all we are presumably dealing with very clever criminals. They may have a way of continuing on from the end of one or the other of these little roads."

Once more he rapped out commands in Spanish, with a final word to the guide. The man nodded quietly. "He will go with two police officers in a jeep, to lead the way," Ramon said. "We will follow in my car."

Sandy opened his mouth to mention the promised sandwiches, but closed it without speaking. It occurred to him that this was a point at which Gonzalez might decide to leave Ken and himself behind. It was even better to go hungry, he decided, than to call attention to themselves in any way. He and Ken moved un.o.btrusively toward the door with the others. Sandy was the last one through. Just as he crossed the threshold, the police chief dashed after him to thrust a newspaper-wrapped package into his hand. Sandy grinned. It was unnecessary to understand the exact words of the swift apologetic explanation.

"Gracias," he murmured, hoping that he was correctly remembering the Spanish for "Thank you."

Neither Phillips nor Ramon made any objection when the boys slipped into the back seat of the black sedan. Gonzalez got behind the wheel and Phillips sat beside him. In an instant they were zooming along the high- INTO THE QUARRY 77.

way once more, back toward El Mante. Ahead of them roared the jeep.

Sandy unwrapped the newspaper, and the white napkin inside it, and revealed a sizable stack of sandwiches made with thick slices of crusty bread. Silently he thrust two over the back of the front seat.

"Thanks. Where'd these come from?" Phillips took them gratefully. Then he swung around. "I'd planned to make you two stay back there! But in all the rush-"

"Where the food goes, there go I," Sandy said, around a mouthful.

Phillips glared. "It's too late to send you back now. But-"

The jeep ahead of them slowed down halfway around a curve and braked to a stop along the right shoulder. Gonzalez pulled on his own brakes.

Phillips, abandoning his argument with the boys, jumped out of the car with the rest to stand bending over the figure of the guide, squatting on the ground in the glare of the jeep's headlights. Past the guide's feet several sets of tire tracks crossed the shoulder and seemed to vanish in the darkness.

"But there's no road here," Ken protested.

Gonzalez had turned a flash on. "Not what you call a road, maybe, but look."

The ground fell away sharply below the shoulder, but the flashlight showed the tire tracks continuing down the steep slope that plunged toward the bottom of a ravine. And when Gonzalez lifted the flash, and directed it at the opposite bank of the ravine, they could all see that the tracks appeared there too.

"This is the quarry road," Gonzalez said. "Come on." He gestured to the jeep driver and the man got back 78 .

into his st.u.r.dy little car, with the guide and the second policeman beside him. Gonzalez returned to the sedan.

The others followed.

"Will your car make it?" Phillips asked.

"Certain cars have already made it," Gonzalez pointed out dryly. "We will at least make the attempt."

They watched the jeep's nose point downward into the abyss. For a moment it seemed to hesitate, and then it dropped slowly out of sight. Gonzalez followed. The big car went over the edge with a sickening lurch. There was a swift skidding drop, as if it were out of control, and then the brakes took hold and the boys could feel and hear the wheels digging into the loose dirt and gravel. They braced themselves by clinging tightly to the back of the front seat.

Then, suddenly, for a few brief yards, the car was jolting across a comparatively level dry stream bed. Up ahead the jeep was already beginning to climb the opposite bank of the ravine. When the front wheels of the sedan tilted the big car upward too, Ramon fed gas to his engine and it growled in response. But slowly the car inched upward, its weight and the extra size of its tires supplying enough traction to overcome the grade. The car finally topped the rise, and its springs seemed to echo the relieved sigh that went up from the four occupants.

But the jeep was now descending another, shallower ravine and the big car turned its nose down again. The ascent on the opposite side, however, was so steep that some crude road making had been done to render it pa.s.sable. The last several yards below the top were gouged out of the crest, so that the tracks rose at a more gradual angle than the bank itself.

When the sedan finally eased itself over the crest, be- INTO THE QUARBY 79.

tween two miniature cliffs of stone, it came to an abrupt stop. The jeep had already halted, immediately ahead.

Ramon cut his lights and the jeep's lights went off too. A moment later the occupants of both cars were gathered in a close huddle. Gonzalez spoke a word of command and the guide disappeared into the night.

"This is the old stone-loading area," Gonzalez told Phillips and the boys. "The trail runs on across it for about two hundred feet to the brink of the quarry. The quarry is not in use now, and is full of water."

"No trail goes on around it?" Phillips asked.

"The quarry backs up against a steep cliff," Gonzalez explained. "There is no way to drive around it. So this is probably a wild-duck chase, but-"

"Goose," Sandy corrected involuntarily.

"Eh?"

Just then a low-voiced call reached them and a flashlight winked from across the clearing. The guide's beam glinted briefly on something bright-the chrome trim of a car.

They all started toward the light instantly, their flying feet raising little clouds of thick dust. And then they were standing in a silent group around the gray coupe. It was empty.

Four more flashlights winked on, in the hands of Phillips, Gonzalez, and the police officers, and swept in wide circles. But of Baron's red convertible there was no sign.

CHAPTER VII.

CONTACT BROKEN.

FOR A MOMENT they all stared blankly at the gray coupe, as if expecting it to explain its presence. There was something confusing in seeing this one car alone, when they had been following the two partnered cars for so many miles.

n.o.body spoke, and only the guide moved. He was still diligently covering the surrounding ground with the light of his small flash. Suddenly the beam's gyrations ceased, and the small, silent man spoke a single word in Spanish.

Gonzalez spun around.

They all followed the direction of his glance and saw what the flashlight illuminated-a set of tire tracks moving toward the edge of the quarry, somewhere ahead in the darkness.

Gonzalez spoke a command, but the guide had not awaited it. He was moving slowly along the tracks, following the marks in the heavy dust with the glow of his light.

His dark hand, thrust sideways from beneath his sc.r.a.pe, brought them all to a halt. The tire tracks ended abruptly at the rocky rim of the quarry pit.

so CONTACT BROKEN 81.

The flashlight beam plunged over the edge and they all peered after it. Twenty feet below them an unruffled expanse of black water reflected the glow of light.

Sandy broke the stillness with his hoa.r.s.e whisper. "Do you suppose they were in it when it went over?"

"I doubt it," Phillips said decisively. "They probably were just getting rid of a conspicuous vehicle. Smart move, of course. And handled smartly. Because if the car's disappearance should be traced to this spot, the conclusion would probably be just that-that Baron and his friend had disappeared too."

"I agree," Gonzalez said. "Our friends are not careless. They do not lose their heads. I think they do not lose their lives either."

"Then do you think they all plan to leave this place in the gray coupe?" Ken asked.

"And where are they?" Sandy added.

"Good questions," Phillips said. "Anybody got any answers?"

There was silence for a moment, and they all stared once more, as if fascinated, at the sight of the tire tracks that disappeared into nothingness.

There was no doubt at all that a car had actually gone over into the quarry pit, Ken was thinking. The edge of the pit between the tracks was slightly crumbled, where the undercarriage of the vehicle had sc.r.a.ped across it during the fatal plunge.

"I suppose," he said softly, "they may have seen us coming, and gone off to hide somewhere until we go away again. Unless they're very close, they wouldn't know who we are. I don't think any of us has been in the light-except the guide, here. If they think we're hunters, who just stumbled on the place, maybe they 82 .

think we'll look around and then leave. Even if they think we're going to report the situation to the police, they might think we'd all go off together to do it."

"That is a possibility," Gonzalez said slowly. "There is certainly no use trying to hunt for men on foot in this rough country and in the dark. I suggest we accept Ken's premise temporarily. We will stare at these tracks a moment longer. We will all shake our heads sadly. We will look once more at the gray coupe. Then-"

"Listen!" Sandy broke in suddenly in a hoa.r.s.e whisper. "I heard something!"

They all kept perfectly still for perhaps thirty seconds.

Then Gonzalez shrugged. "I don't-"

"Sounded like a car motor," Sandy insisted.

"Sandy's got ears like radar," Ken murmured. "If he says he hears something, there is something to hear."

"Oh!" Sandy let out his breath. "Just an airplane, I guess. I can tell now that the sound comes from up above somewhere."

"All right," Phillips said briskly, "if we're going to put on this act in the hope of luring them back here, how do we play the final scene? Are we going to drive both our cars away?"

"Exactly," Gonzalez said. He paused for a moment, in concentration, and suddenly they could all hear the faint throbbing sound that had caught Sandy's attention.

"The cars will return to the highway," Gonzalez went on. "Then, Mort, you and I and the policemen here will conceal ourselves at the bottom of that ravine."

Ken suddenly grabbed the Mexican's arm. "Is there a regular airplane route above us here? Do planes often cross this part of the country at this hour?"

CONTACT BROKEN 83.

Gonzalez stared at him for a moment, and in the silence the throbbing overhead grew louder. Then the Mexican turned swiftly toward one of the police officers who had accompanied them from the Antiguo Morelos station. He snapped out a question in which Ken caught the word aeroplano.

"No, Capitan." The answer was quick.

Gonzalez prodded with another question, longer and obviously more explicit.

The same answer was repeated. "No, Capitan."

"This is not a regular route. Planes pa.s.s over here very seldom." Gonzalez twisted his head to look up into the sky.

Ken spoke aloud the thought that had leaped to his mind. "They're not transferring to the gray coupe They're transferring to a plane!"

This time Gonzalez snapped his question to the guide. The small man deliberated a moment and then shook his head.

"He says there's no place around here big enough for a plane to land," Gonzalez reported.

Phillips breathed his relief. "Good! We'd certainly have no chance to follow a plane."

But they warily listened for a moment longer. Now the throbbing seemed to fill the whole dark night.

"It's not a big transport," Sandy said. "Must be a single-motor job."

"There it is!" Ken said suddenly.

They all swung to look in the direction of his gaze. The sky was slightly clouded over. The dim starlights that patterned it here and there were all motionless.

"I saw a blue exhaust flame a second ago," Ken insisted. "See? Right there!" He pointed back toward the direction of the highway, and an instant later they all 84 .

saw the faint blue blur he had noticed. It was heading toward them.

Sandy had been straining his ears. Now he said softly, "That's no plane! That's a helicopter."

"A helicopter!" Mort almost shouted the words. "Then it wouldn't need much s.p.a.ce to land." He swung toward the guide but Gonzalez was already questioning the man in a rapid fire of Spanish.

This time the man didn't hesitate before he replied. Nodding his head vigorously, he pointed across the quarry to the top of the cliff that rose beyond it. The crest of the rock wall was faintly visible, a more solid black against the black of the sky.

Ken followed his pointing finger and then he swung back toward the direction of the throbbing sound.

"Look! A green flas.h.!.+"

The stabbing green light went on three times, at short intervals, and then the sky in that quarter was completely dark again.

"It's a signal!" Ken exclaimed. "He must be getting ready to land."

The throbbing sound was almost overhead now, and still coming closer.

Ken looked again at the cliff toward which the guide had pointed. He was just in time to see a green light glowing there for an instant before it disappeared.

His hoa.r.s.e cry brought the others around and they all saw the next two flashes of green from the cliff.

"That's the landing field all right, up there." Phillips spoke between clenched teeth. "We'll never get them, once they take off. Ramon!" He spoke rapidly, with his hand clamped around the Mexican's arm. "It's too late now-if they take off for the hide-out, we can't follow. The next best thing is to stop them before they leave.

CONTACT BROKEN 85.

We'll at least get Baron and the money. Can we get to the top of that cliff?"

Gonzalez spoke swiftly to the guide and the guide nodded.