AS TOM AND BUD stared anxiously, the mechanical birds darted in and out of the clouds, cutting in front of the Sky Queen.

"Three of them are making a pa.s.s over the rudder," Bud warned. "What say we run before they ruin the ship?"

"Not yet," said Tom.

The young flier constantly checked the instrument gauges. If they suddenly fluctuated, he would know the mysterious force behind the crows had penetrated the protective coating of Tomasite. Minutes pa.s.sed with the crows circling and weaving across their flight path, but Tom retained complete control of the Flying Lab. Turning to Bud, he said: "I didn't think their beamer-or whatever that force is-could get through."

"Good night!" Bud cried. "There's another flock! How many can we hold off?"

39.

40 .

"I'm beginning to think that if one crow can't hurt us, neither can a hundred,"

Tom said confidently.

As the weird parade moved through the threatening skies, the boys watched the strange scene, almost hypnotized.

"What's our next move, Tom?" Bud asked finally. "Do we dare send out the drone?"

"I don't believe so, Bud," Tom replied thoughtfully. "We don't know how strong the crows' force may be, nor how far their operating field extends. Once the drone is outside the hangar, it won't be protected by the Queen's Tomasite shielding."

"Hm-m, you've got a point there," Bud said, a vision of the drone falling to its doom crossing his mind. "Drones are valuable equipment."

Tom's mind was working rapidly. In a moment he had the answer. "Bud, there should be a distorter aboard," he said. "If I install it in the drone I'm sure it can resist any beam the crows throw out."

"Swell idea, genius boy. Want me to take over here?"

"No, I'll need your help installing it. Set the Queen on the lifters and leave her."

As Tom dashed from the cabin, Bud switched off the forward speed jets, clicked on the lifters so the ship would remain stationary in the air, then followed his friend down the stairs to the storage-inventory closet.

Tom thumbed through a rotary wall file and A RARE CAPTURE 41.

quickly located a card with information that a distorter, his own invention, would be found tied down to storage rack number ten. This device was capable of scrambling electrical signals and remote-control beams.

He and Bud carried the instrument to the sliding door that separated the hangar from the rest of the first level. Tom opened it and they clamped the distorter in the sleek drone, connecting the cable to the drone's generator.

Tom started the dynamo and its high, singing screech filled the hangar. Bud felt better already. "Maybe we can nab the whole jet flock." He grinned.

The distorter installed, Bud activated controls releasing the drone's lashing and wheel blocks.

"Prepare to disgorge!" he yelled. "Start her up, skipper!"

Tom pressed the drone's remote-control starter and the hangar doors swung open automatically. A crow shot past the opening, veering to miss the jet stream.

"Set, Bud?" Tom yelled.

"Set! Let's give these mechanized corn feeders a taste of their own medicine!"

Tom threw a switch and for a brief moment the drone's thrust blasted hot gases back through the hangar. Then, with a roar, it leaped forward and careened through s.p.a.ce after the marauding crows.

Bud and Tom raced back to the pilot's compart- 42 .

ment. "Look at that drone go!" Bud cried, tracking it from the navigation dome's seat.

The powerful little plane whipped in and out of the flock, but the crows seemed to sense its approach and dodged out of the way. Although they managed to avoid the drone for several minutes, whatever was operating them suddenly seemed unable to control the separate maneuvers of the whole flock at once.

"We've caught one!" Bud yelled jubilantly as the drone sucked the bird alongside it. "And another!"

A moment later the rest of the flock flew off at great speed.

"We've got 'em on the run now, Tom!" Bud cried exuberantly. "Let's follow as soon as the drone's berthed."

He dashed back to the hangar while Tom got ready to give the Sky Queen the gun.

Tom directed the drone to a reverse blast landing, while Bud manipulated the arresting gear controls from the hangar. When the drone and its two trophies were safely berthed, Bud phoned Tom, who gave the Flying Lab a powerful forward thrust, and the Sky Queen soon overtook the crows. The copilot joined his friend.

"I'll follow them for a while," Tom said, slowing his huge ship to match the crows' speed. "Watch for signs of a possible control station."

Bud peered down through binoculars. He spotted familiar landmarks-local farmhouses and factory A RARE CAPTURE 43.

buildings well known to both boys-but nothing that would suggest a control- station housing.

"These birds will have to lead us somewhere," Tom said.

As if in answer, the entire flock suddenly nosedived. Tom dropped the Sky Queen.

"They're headed for that big open section of Riverton Lake!" Bud yelled.

"They'll probably turn in a second," Tom replied, then gasped incredulously.

In a series of resounding splashes the crows smacked into the water and disappeared.

"Well, how do you like that!" Bud exclaimed in disgust.

Tom switched on the jet lifters and the Lab hovered over the lake.

"Maybe the crows have a water base," Bud suggested.

"I doubt it," said Tom. "Their owner didn't want to reveal his base of operations. We were getting too close for comfort, so he crashed them. He must have a lot more hidden some place, though, or he wouldn't have destroyed so many."

"It was a smart maneuver, all right, sending them to the one place we can't follow," Bud observed.

They crisscrossed the area several times, but failed to find any clues to the hide-out of the owner of the strange missiles.

"We may as well head for home," Tom said. '"I 44 .

hope that Billing picked up something." Turning over the controls to Bud, he added, "I'm going down to the hangar and take a look at those crows."

"Good idea," Bud replied. "Let me know what makes those babies tick!"

A few minutes later the buzzer sounded in the pilot's cabin.

"Bud, these crows are fantastic looking at close range," Tom reported. "But I can't see what makes them work without taking them apart. Think I'll wheel one to the physics lab and take a look."

"Roger," Bud said, and pointed the ship toward Shopton.

Yawning and stretching his shoulders, Bud rode the controls lightly. The Sky Queen's smooth flight was relaxing after the afternoon's excitement.

"Wonder what Tom is finding out about those crows," Bud murmured. As he was about to pick up the intercom to find out, an explosion rocked the huge ship!

Bud grabbed for the wheel of the yawing plane with one thought burning in his mind. The explosion must have been in the physics lab!

"Tom!" he yelled in horror. "Tom!"

CHAPTER 6.

NARROW ESCAPE.

FEARING THE WORST, Bud set the Sky Queen on stationary position and hurried toward the laboratory. By this time the ship was filled with an acrid smoke that burned Bud's eyes and made him choke.

He stopped a split second to grab a gas mask from a wall closet, then raced on. His heart pounding in dreaded antic.i.p.ation, Bud flung open the laboratory door. The huge place, with its many sections, was blanketed with smoke.

Bud dashed from room to room. His friend was not in any of them.

Furthermore, it was evident from the little damage in the laboratory that the explosion had not occurred there. But where had it been? And where was Tom?

Heartsick, Bud started down the stairs to the hangar deck. The smoke was thicker here. But through it he could dimly make out another gas-masked figure.

45.

46 .

"Tom!" he exclaimed. "Thank goodness! I thought you-"

The m.u.f.fled sounds reached Tom, who rushed to Bud's side. "I'm okay, Bud.

The explosion was in the hangar. It wrecked the sprinkler system. The fire's getting out of control!"

"How about using the bags of sand? We can toss 'em in," Bud suggested.

"No, the fumes are too strong. They'd soon deactivate our mask purifiers."

"What'll we do?" Bud asked, knowing moments of delay were costly. The whole ship might go!

"Get the robot and the control board," Tom replied. "Bring them here. I'm going to the lab for some powerful fire-fighting chemical."

The boys dashed off. Each worked like a demon to accomplish his task. Bud was waiting in the smoky corridor when Tom returned with two fifty-pound cylinders of methyl bromide and a few yards of plastic pressure tubing with a nozzle attached to one end.

"Can you control Walter from behind a closed door?" Bud asked.

"Yes," Tom answered, uncoiling the hose and attaching it to the valve on one of the methyl bromide cylinders. As he began to twist open the cylinder's needle valve, Tom asked Bud to raise one of the robot's arms and tie the nozzle of the hose to it. When everything was ready, Tom jumped to the control panel, saying: "Open the door, Bud."

NARROW ESCAPE 47.

Simultaneously one boy pushed a b.u.t.ton that controlled the hangar door while the other set the robot in motion. As Walter clumped forward into the hangar, tongues of flame spit from the opening and fierce heat waves rolled into the corridor. Bud closed the door, leaving a crack just wide enough for the hose.

"Here goes the first cylinder," Tom yelled, opening wide the valve. "Get the second one ready, Bud."

Dial needles on the control panel fluctuated wildly as Tom moved the robot through the blazing hangar. When the first cylinder of chemical was used up, Bud quickly uncoupled the hose and transferred to the second.

Within fifteen minutes the robot's valiant battle in the hangar became a victory. The final tongue of flame was snuffed out.

Tom and Bud had to wait until the ship's air conditioning cleared out the fumes before they could remove their masks. When they were able to enter the hangar, the boys could not touch the hot, twisted parts of fused metal that had been the drone plane.

The crow was in minute pieces, scattered about the hangar. Bits of it had pitted the walls and ceiling.

"What do you think caused the explosion, Tom?" Bud asked.

"From the looks of things," Tom answered, "I'd say the crow exploded, taking the drone and almost the entire hangar with it." Suddenly a look of horror crossed his face. "The other crow!" he cried. "It's 48 .

still in the physics lab. That may explode too!"

Leaping up the stairs two at a time, they dashed into the physics section. The huge mechanical crow was lying on the worktable where Tom had left it, wings outspread and feet sticking up in the air.

"We'd better pitch this thing overboard p.r.o.ntol" Bud advised, starting to lift it.

"No!" Tom cried. "Don't do that. I'll never be able to learn what's inside."