There was a public telephone on the inner wall of the little refreshment stand and a moment later Phillips was rattling Spanish into it.

"We could have said we'd leave him right here," Sandy muttered.

Ken didn't answer. Instead he said, "Three cars in a CHANGED PLANS 35.

row-red, black, and gray. Who's following whom? And how does Phillips fit into the picture?"

Sandy jabbed him in the ribs with a sharp elbow. "Answers to both questions," he pointed out, "are none of our business."

"I suppose not. But-"

Phillips was coming back toward them. "It'll take too long to get my call through. I'll make it from Monterrey." Despite his easy manner he seemed restive and anxious to get started. "You finished now?"

Ken and Sandy handed him their empty bottles and a couple of peso notes. And then they were on their way again, traveling once more in the silence that had marked the first part of the trip.

Vallecillo fell behind them and, some fifteen minutes later, the sizable town of Sabinas Hidalgo. And beyond Sabinas Hidalgo the road finally began to climb and twist up into the mountains.

Phillips glanced down at his watch. The time was shortly after eleven. "We're crossing a spur of the mountains we've been seeing on our right," he said. His tone was casually informative, but he was leaning forward slightly, as if to urge the car ahead.

But now the road switched back on itself every few hundred feet, in hairpin turns, and the speedometer reading dropped down below thirty miles an hour. Ken rounded a sharp corner and found himself behind a heavy Diesel truck, belching black smoke as its engine labored. The truck was crawling upward at scarcely more than five miles an hour.

The smoke billowed around them. Ken edged out to the left to pa.s.s the big vehicle, but ducked back in line when he saw another turn directly ahead. Beyond 36 .

that turn he tried it again, but once more the glimpse of a sharp corner a few hundred feet beyond the truck forced him to fall back.

"Toot your horn," Phillips said impatiently. "Then the truck driver will let you know if you can pa.s.s." He laughed suddenly and apologetically. "Sorry. Didn't mean to tell you how to drive your car."

"That's O.K." Ken tapped the horn twice. Almost immediately the taillights of the truck blinked.

"He's telling you the road's clear," Phillips said.

Ken stepped down hard and swung to the left. As he raced past the cab of the truck, the driver waved them cheerfully on.

There seemed to be no end to the turns or to the climbing. Each sharp curve seemed to bring them within sight of the crest of the pa.s.s, but beyond that turn the road was always still climbing further. Far below them they could sometimes catch glimpses of the twisted thread of road they had come over. Once they saw the Diesel truck still laboring forward, miles behind them now, like some sluggish insect inching its way upward.

And then, suddenly, they did reach the top of the pa.s.s. The road leveled off for several hundred feet, then began to drop as rapidly as it had climbed.

Ken was pumping his brake pedal around a particularly sharp curve, about a mile below the summit, when Phillips shouted: "Stop! Look there! Somebody went over the edge! Stop!"

They were a hundred feet beyond the skid marks before Ken could bring the convertible to a halt. The tire marks ran straight toward the outer edge of the road and across the shoulder that ended at the lip of a sharp CHANGED PLANS 37.

drop downward. The guardrail at that place on the shoulder had been ripped away.

Phillips was out of the car even before Ken could pull the hand brake up and kill the engine. The boys tumbled out after him in time to see him disappear over the edge at the place where the rail was broken. When they, too, reached that place they could see Phillips some distance below the level of the road, plunging down the steep slope in flying leaps. He was already halfway down toward the black sedan, which lay on the slope on its side. The thick clump of brush, against which the overturned car rested, had obviously prevented it from cras.h.i.+ng clear to the bottom of the canyon, several thousand feet below.

Ken and Sandy hesitated only a moment. Then they started down the slope, digging their heels into the ground at every plunging step to keep themselves from sliding downward in an uncontrollable rush.

Below them, Phillips reached the sedan, landing beside it in a cloud of dust. They could barely see his figure as he peered downward through the windows. As the boys landed at his side he looked up and around.

"Ramon!" he called sharply. "Ramonl"

"Sil Si! Coming. I am here." A figure was crawling slowly toward them from the far side of the brush-a small compact figure of a man with torn clothes and a bleeding face.

Phillips moved swiftly in his direction. "You all right?"

"Yes, Mort." The man spoke English with a marked Spanish accent. "Just bruised and scratched." He grinned, and his teeth were startlingly white in his swarthy face. "And very lucky."

38 .

"When I didn't see any sign of you," Phillips said, "I_ The Mexican smiled again. "I was-how do you say? -playing possum. In case our friends returned to-" His glance fell on the boys and he broke off abruptly. "But I can give you the details later, no?"

Phillips nodded. "As long as you can walk-"

"Perfectly. And with a little soap and water I shall be nearly as good as new."

"Fine! Then let's get going."

Ken took a deep breath. He had immediately recognized the man Phillips called Ramon. He was the "friend" with whom Phillips had mysteriously conferred while they ate breakfast in Nuevo Laredo, and the big black sedan was the antenna-equipped car which had been parked in front of their own convertible. Phillips must have known that the black car was traveling south along the highway-and yet he had asked the boys if he might ride with them.

"Wait a minute," Ken said, as Phillips took his first step back up the steep slope. "How do you plan to travel -from here on?"

Phillips looked at him sharply. "I a.s.sumed I could remain your pa.s.senger as far as Monterrey," he said. "And I took for granted you'd play good Samaritan to a friend of mine who's been in an accident. We've both got good reason to want to get to Monterrey in a hurry. So let's get started-if you've got no objection."

"I think we have," Ken said slowly. "If your friend had been seriously hurt, we couldn't do this, of course. But he insists he's all right, so-well, I think we'll bow out here. I gather he was forced off the road. We'd just as soon that didn't happen to our car, because he was CHANGED PLANS 39.

riding with us. Maybe that big truck coming along behind will pick you up. Come on, Sandy."

Together, he and Sandy turned and started back up the hillside. They had taken only a few steps on the steep slippery slope when Phillips' voice spoke.

"Wait!" The single word barked out on a note of sharp, decisive command.

Ken took another step upward, but he glanced back over his shoulder-and froze.

"I can understand your wanting to get away from something that doesn't concern you," Phillips was saying levelly, "but we need you for a little while longer. And I'm afraid we're going to have to insist upon your co-operation."

The words were hardly necessary. It was the heavy automatic in Philhps' hand that provided the most convincing argument.

CHAPTER IV.

PURSUIT.

KEN'S EYES riveted themselves on the gun in Phillips' hand. Sandy had seen it now too. Ken knew that from the redhead's quick intake of breath. And Ken was also aware of the fact that Sandy and himself, against the steep hillside, presented targets that could not possibly be missed.

Sandy turned to face down the slope, cautiously s.h.i.+fting his weight. Ken knew what was in his mind. The same idea had occurred to him. Their only chance against that gun was a sudden downward rush that- Phillips was speaking again. "I want to talk to you," he was saying in his level voice. "But first look at this. Catch!"

Even as he said the word a small black rectangle came flying through the air. Instinctively Ken put up his hands and caught it. His fingers closed around smooth leather.

Dazedly his mind registered the fact that he held Phillips' wallet. And his eyes told him that Phillips was suddenly, inexplicably, grinning.

"Look at my credentials," Phillips said.

"We've seen them. We-"

40.

PURSUIT 41.

"I don't mean my tourist visa and my school registration." The gun lifted slightly in a gesture that was both impatient and menacing. "Look in the back section."

The voice and the gun were both compelling. Slowly Ken opened the wallet.

Words leaped up at him from the official-looking ident.i.ty card. Sandy saw them too, and repeated them in a voice that was loud with astonishment.

"Federal Bureau of Investigation!"

"You don't have to advertise it to the whole countryside." Phillips turned to the Mexican beside him. "Show them yours too, Ramon."

The Mexican shrugged. "If you wish it, Mort."

This time the wallet they opened was brown and battered, but the ident.i.ty card in the back had the same official air. The printed words were in Spanish but their meaning was clear. Ramon Arturo Fernandez Gonzalez was a representative of the Mexican Federal Police.

Ken raised his arm to toss them back and then changed his mind and walked slowly forward, down the slope. Sandy moved along beside him. "All right," Ken said, knowing that the grin on his face must look a little foolish. "What did you want to talk about?"

Phillips was casually shoving the gun back into a shoulder holster concealed by his jacket. "Sorry about the melodramatics," he said, "but I couldn't have you go das.h.i.+ng off down the road carrying some pretty dangerous knowledge-and not knowing it."

The Mexican fired a rapid question at Phillips in Spanish.

Phillips grinned at him wryly. "How much do they know? Well, for one thing, they know you aren't dead -a fact our friends probably are not aware of yet. And I don't see any reason why those gentlemen should learn 42 .

it. I also suspect," he added, "that neither of these boys believed my story of being a student at the National University." He eyed them questioningly.

"I was getting pretty suspicious of you," Ken admitted.

"But we didn't think you were-well, what you really are," Sandy added.

"You weren't supposed to," Phillips told him. "And I'm sorry you had to find out." He turned to Ramon. "Now that we've commandeered a car, let's use it. We can do the rest of our talking on the way."

"Good," the Mexican police officer agreed. "But first I will check the transmitter in my car. It is possible that it still operates."

Phillips looked at his watch. "How long ago did your 'accident' occur?"

The Mexican calculated swiftly. "Fifteen minutes ago, I would say."

"That would give them a chance to get beyond the next inspection station," Phillips muttered. "But maybe we can still catch them at Cienega de Flores. That'? about eleven miles farther on, isn't it?"

The Mexican nodded. "It is worth the try." He had already squirmed up to the window of his car and now his head disappeared downward into the s.p.a.ce in front of the dashboard.

After a few brief moments the loud-speaker in the car erupted into Spanish. The Mexican listened until the rapid speech came to an end, and then he answered it into his microphone. The boys could understand nothing of what he said except a scattering of si's and no's and the name Cienega de Flores. When the Mexican rejoined them on the ground again he was nodding with satisfaction.

PUKSUIT 43.

"It is good," he told Phillips. "Both cars have pa.s.sed the inspection post but neither has reached Cienega de Flores. Fortunately, there is an agricultural inspection station there-the guards search cars for any plants that may harbor the black fly." His white teeth flashed. "The two cars of our friends will receive a very thorough searching indeed. It may require half an hour or even more."

"Fine." Phillips grinned back at him. "And now let's get going."

Ken and Sandy glanced briefly at each other as they all started to climb back up the hill to the road. Sandy still looked slightly baffled at the sudden turn of events. Ken felt baffled too, but he also admitted to himself that he was extremely interested.

"Something tells me," he murmured quietly to Sandy, "that we are about to acquire the facts on a pretty lively story that will interest Global News."

At the top of the hill Phillips checked the road, to make sure that there were no other cars in sight before they all crossed the shoulder to the parked convertible.

"You get in the back, Ramon," Phillips said. "And keep down out of sight."

Ken slid behind the wheel and Sandy got in beside him. Phillips followed and shut the door. "O.K.," he said. "Let's go."

As Ken eased the car around the first sharp curve, Phillips leaned over the back of the seat to speak to his confederate. "My opinion is that you ought to leave us at the customs inspection post," he said. "You can pick up another car there and follow as soon as possible. And arrange for a crew to get your own car back up on the road, of course."

44 .

"Si." The Mexican's voice was slightly m.u.f.fled but iheerful. "I agree. And you?"

Ken sensed that Phillips was looking directly at him as the man answered, "You'd better arrange for a car for me too, to be picked up at the earliest possible post."

Ken's news sense, already aroused, prompted his words. "A minute ago you were demanding our car at the point of a gun," he said. "And now that you've got us interested in whatever it is you're on the trail of, you're apparently going to shove us out of the picture."

"No, es posible-" The spurt of Spanish from the back seat broke off and began again in English. "It is not possible to report anything of this case to the newspapers."

"We wouldn't use anything that hadn't been checked with you first," Ken began stiffly. "We-" He stopped suddenly. "How did you know we had any connection with a newspaper?"

Phillips answered him. "We know everything about you," he said. "We know about all the sc.r.a.pes you've been in in the past. We know when you left Brentwood -why you were held up two days in Texas."

The car lurched slightly as Ken twisted sideways to stare at Phillips. Sandy was staring at him too, his eyes wide with amazement.

Ken recovered his voice. "How?" he demanded.

Phillips grinned faintly. "It's a long story, and there's no point in going into it now. The next important item on the agenda is for us to get rid of Ramon, here, and then for you to get rid of me as fast as possible. I wouldn't have asked a ride from you in the first place, if I hadn't been in a spot. And the same is true of using your car right now, in this further emergency."