Bud examined the wreckage for a rope, but there was none aboard. There were, however, control cables. These were built into the fuselage and ran from the cabin to the engine and rotors.

Reaching for the emergency tool kit, the pilot clipped long lengths of cable and spliced them together. It was a slow, drawn-out process. His hands were blistered and raw when he finished the final splice.

Using the cable as a la.s.so, Bud looped it around a projecting stone. Then, after filling his pockets with tools, he pulled himself up to a ledge a few feet above. From there he was able to risk throwing the line to Sandy. She leaned over the edge, with Phyl clutching her ankles.

Sandy missed the cable on the first toss but caught it on the second throw, and tied it around what seemed to be a rather firm pillar of stone. Bud gave the cable a few preliminary yanks. The stone crumbled.

"Wow!" he gasped as the pieces of rock fell past him.

The next time, the girls anch.o.r.ed the cable firmly around a deeply embedded boulder. The line held, and Bud, after wrapping it twice around himself, leaned back into s.p.a.ce and began to pull himself upward.

Progress was slow and painstaking. Bud lifted one MAROONED ON THE MESA 143.

foot cautiously above the other, swaying to maintain his balance. It was twenty minutes before he was safely beside the girls.

"Thank goodness!" both girls cried, hugging him in their relief.

Bud grinned, but he was too physically exhausted to make one of his usual wisecracks. It ^vas many minutes before the full import of the situation dawned on them. Many hours would pa.s.s before they were reported missing and a rescue party sent after them.

"At least we're all safe," Sandy remarked philosophically.

"But the crows may return," Phyl said worriedly.

Bud shook his head hopefully. "I believe that they've done their work for today." He looked down at the badly mangled helicopter and thought of how close they had come to total disaster.

Their situation, nevertheless, was far from pleasant. They were without food or supplies. The chance of a stream on this barren mesa was nil. Should they have to remain past sundown, they would suffer from the night's intense cold, since they were not warmly dressed.

Bud, realizing the urgent need for psychology to keep the girls from becoming frightened, sprawled out casually on the ground and scooped up a handful of earth. "Do you think that the legend about buried Indian treasure on Purple Mesa could be true?" he mused aloud.

144 .

"I'm sure it is," said Sandy, brightening.

"The legend says its fabulous," Phyl added. "There are supposed to be hundreds of hand-carved necklaces, solid-silver brooches, and bracelets set with precious stones."

"Then let's start digging," Bud urged, relieved that he had been able to divert the girls' minds from their plight.

Phyl and Sandy eagerly discussed the most likely spot to search.

"If I were an Indian I'd bury the treasure near that fissure," said Bud, indicating an uneven crack in the ground. "That way I'd have a marker and know just where to find it."

Phyl did not agree. "No wise Indian would do that. It would be too obvious."

Using the tools Bud had taken from the helicopter, the trio began digging for the legendary treasure. Each one chose a different area to explore.

By midafternoon there were a dozen miniature foxholes on the mesa top.

The girls were beginning to tire.

"Maybe we'd better rest for a time," Bud suggested.

"But we may never come here again," said Sandy. She tossed a scoopful of earth over her shoulder and continued to dig. "Think of all that treasure!" she said.

Bud grinned, shaking his head helplessly. "Carry on, girls. I'll just supervise for a while."

MAROONED ON THE MESA 145.

He sat on a flat rock and watched with mounting skepticism as the girls plowed up the surface of Purple Mesa. Suddenly a shriek of joy sent him leaping to his feet. Fifty yards away, Phyl was jumping up and down, shouting, "We found the treasure! We found it!"

Bud dashed over to where Sandy was holding an object aloft. After she had sc.r.a.ped the caked earth from it, Bud whistled in amazement. It was an ancient turquoise-and-silver ring!

"I can't believe it!" he said in astonishment. "Let me have one of those tools!"

In no time he too had forgotten that the trio were cut off from civilization. For hours the three clawed at the earth, digging one hole after another. The sky turned scarlet, then magenta. Finally the weary searchers were forced to give up as dusk came on. The treasure hunt was at an end with only one ring to reward their efforts.

Now Purple Mesa took on a rather eerie aspect as lengthening shadows of lavender and violet crept across its surface. Deeper purple hues cast an unreal pallor on their faces. The cold of the desert night began to make itself felt.

"If only we had a fire!" moaned Phyl, her teeth chattering.

"I'm getting hungry," Sandy said wistfully.

Bud remained silent. His eyes watched the ever-darkening skies for some hopeful sign of a rescuer.

"Tom will be here," he said. "When we don't re- 146 .

turn on schedule, he won't waste a minute in starting 3. search."

As the last ray of daylight filtered out, the powerful beams of the Sky Queen's landing lights appeared on the horizon. The huge ship thundered toward them until it was directly overhead. The Flying Lab hovered over the mesa and began to descend.

The three marooned below waved frantically. Tom, relieved to see them alive and safe, blinked his lights in answer. He held the ship motionless in the air, keeping the intense blast of the jet lifters away from the trio on the mesa.

Because of the fiery blast, a landing would be impossible.

A solution to the rescue problem soon became apparent to Tom. First he maneuvered the Sky Queen over to the edge of the precipice and then slowly permitted the ship to sink down until she was slightly above the mesa top. The doors of the bay were opened, and Sterling and Hanson hurled down a flexible metal ladder. On the third try Bud caught it and managed to hold it taut while first Phyl, then Sandy, scrambled to the safety of the Sky Queen.

With no one to anchor the ladder, Bud realized that as soon as his feet left the ground the ladder would swing under the belly of the Sky Queen and expose him to the intense heat and air blast of the jet lifters. He wondered if he would be able to climb up, hand over hand, fast enough to escape being blown off the ladder. It was a chance he would have to take.

MAROONED ON THE MESA 147.

Stepping onto the first rung, Bud felt the ladder swing forward. Quickly he reached up and grasped the next rung, and the next and the next.

"Hurry!" cried Sandy from the bay.

But speed on the twisting, swaying ladder was out of the question. It was all Bud could do to hang on. Terror in his eyes, he looked at the lifters.

The next moment, the ladder was swept toward the fiery blast!

CHAPTER 18.

ROBOT TENNIS.

TOM INSTANTLY REALIZED that only one course of action could save Bud- to put the Sky Queen into forward motion and cut off the lifters. But he must do it without the slightest jar or Bud would be flung off into s.p.a.ce.

"Hang on, everybody!" he shouted through the loud-speaker system, switching off the lifters and easing the great ship into a slow, downward glide away from the mesa.

With hope in his heart he looked below. Bud was still hanging on! And the ladder was being pulled up at lightning speed by Sterling and Hanson. Tom set the plane on automatic pilot and raced to the Flying Lab's hangar. He was greatly relieved to find Bud there.

"Bud!" he cried. "Boy, am I glad to see you safely aboard!"

148.

ROBOT TENNIS 149.

His sister was already insisting upon dressing Bud's injured hands, though the youth said that it wasn't necessary.

"Sandy's right," said Tom. "Go to the infirmary and get fixed up. Phyl, you come up front with Hank and Arv and me and tell us what happened."

When he heard the story Tom cried, "The crows again! Did any of you see a plane around from which the birds might have been controlled?"

Phyl shook her head. "There wasn't any as far as we could see."

"It must have been above the clouds," Hank offered, and since there was no other solution, they accepted this explanation.

Sandy and Bud joined the others then, commenting ruefully on the whole experience.

"And on top of everything else," Sandy said with disgust, "we found only this one ring out of all that legendary treasure!"

Tom grinned. "Too bad, Sis. Would you like to come back and try again?"

"No, thanks, Tom. I'm convinced now that there's more legend than treasure on Purple Mesa!"

Tom announced that in the morning they would try to rescue the Skeeter.

"We'll rig a winch and cable at the hangar doors. The wreckage can be secured with grappling hooks."

Directly after breakfast the next morning, Tom and his friends set out for Purple Mesa in the Sky Queen.

150 .

The winch-and-cable mechanism, rigged to avoid the jet lifters, projected on a boom out into s.p.a.ce. Tom had to leave the hangar doors open, giving the usually graceful Sky Queen an ungainly appearance.

"What's worse," Bud complained, "it cuts down our speed and chances to maneuver. We're wide open to an a.s.sault."

Tom agreed that the device made the ship vulnerable. "We'll have to stand by with an ax to cut the mounting loose in case the crows attack."

But the ship was not molested. Reaching the cliff-side, Bud took over at the controls. Tom insisted upon riding down on the cable to make an inspection of the Skeeter himself and attach the grappling hooks.

Grasping the metal ropes, his feet firmly planted in the clawlike hooks, he was lowered by Sterling while Hanson worked the winch. As he surveyed the badly damaged helicopter, which would need extensive repairs, the young inventor was beside himself with anger. Someday, he told himself, the scoundrel responsible for the savage attacks would be caught and punished by the law!

Moving about cautiously in order to keep his balance, Tom attached the grappling hooks to the Skeeter. He made sure that they were firmly secured, then signaled to the engineers above.

"Haul away!"

The derrick groaned, reduction gears spun, and the Skeeter, with Tom balancing on its roof, was ROBOT TENNIS 151.

lifted through the air. Once a strong wind current rocked it violently and Tom had to bear down heavily on a guy rope to keep from being tossed off.

The boom swung in. Tom ducked to miss the hangar ceiling and jumped off onto the deck.

The Skeeter was aboard and Tom was safe!

Bud piloted the Sky Queen back to the Citadel and set it down a few miles outside the enclosure.

Tom told the others that he would like to leave for Shopton that afternoon and asked them to be ready. "I've done all I can at this end of the line. The next job is giving my giant robots their final tests before shipping them out here."

Tom went off for a conference with his father before leaving. He found Mr.

Swift in his office talking to Robert Turnbull. The latter seemed to be very upset.

"I-I don't know what you're talking about, Mr. Swift. I am in perfect health. I never felt better. I'm thoroughly calm, thoroughly calm."

Mr. Swift replied quietly, "It has always been the policy of my company to extend leave with full pay to any man involved in family stress. You say that no trace of your twin brother, Raymond, has been found. This naturally worries you.

Why don't you take a vacation?"

"I'm sorry, Mr. Swift," replied the atomic scientist. "My work comes first.

Things are at a critical stage here. I cannot shirk my part in it because of personal troubles."

152 .

There was further conversation but Robert Turn-bull made it quite clear that he would not accept a vacation. He turned and left the room.

"Well, you have to give him A for loyalty," Tom remarked, then told his father of his plans to leave. "I'm sure that there won't be any trouble setting the other drone planes in flight when they arrive."

Mr. Swift smiled. "I'll feel a lot safer when they're at work, Tom. By the way, if you're satisfied with the tunnel, we'll line it with cement and put in the Tomasite- coated door to the bas.e.m.e.nt."

"Everything's to specification, Dad. And I'll see you again in about two weeks."

"Fine, son," Mr. Swift said, clapping Tom on the back, "and in the meantime we'll try to track down the interference inside the plant that made Stan Lee topple over. Then, when you return, we can put the giant robots right to work."

The trip back to Shopton was uneventful. Tom and Sandy had dinner with their mother and spent the evening with her. Tom learned that Pins Zoltan had left the hospital and was in police custody. He had been subjected to intense questioning for over forty-eight hours by the police department's top crime probers, but had not cracked. There was no word on either Flash Ludens or Slick Steck. And Marco too was still unaccounted for.