Rick was literally stunned. He turned to Barby and Scotty and he just couldn't say anything. Neither could they. Scotty's mouth was open with surprise and Barby's blue eyes were wide.
The unexpected had struck Rick Brant forcefully a number of times before. However, the unexpected was a part of adventuring. There was once, in The Lost City, when Ghengis Khan, a Mongol ruler who had been dead for centuries, had miraculously appeared. His strange appearance had been unexpected, but none the less welcome, because it had saved Rick and his friends from certain death in faraway Tibet.
And Rick would never forget the time, as related in Sea Gold, when he had been forced to run for his life through the maze of the New York subways. The sudden discovery of his pursuer's identity had been the most shocking thing he had ever experienced.
One came to realize that strange places always brought the unusual. Similarly, however, one had the right to expect serenity and a certain consistency in the sequence of events at home. That is why the shock of realizing the familiar rooms of the laboratory were barred to him was much greater to Rick than anything that might have happened on an expedition.
Barby found her voice first. She sounded very subdued. "Golly, I never thought anything like this could happen."
"None of us did," Scotty said. "But it's happened. Now what do we do?"
"Nothing." Rick was getting angry now. The least that was due them was some word of explanation.
"Take it easy," Scotty said. "Don't do or say something you'll be sorry for later."
Barby nodded agreement, her eyes on Rick.
"Okay." He agreed reluctantly. "I don't fly off the handle. But when the explanation comes, it had better be good."
"It will be," Barby said hurriedly."Rick, what are we going to do about Dismal?"
That was Barby's way of changing the subject, Rick knew. He grinned at his sister."We'll do just what we planned." He rapped on the laboratory door again.
When the door opened this time, it revealed a short, stocky man with close-cropped gray hair. He was Professor John Gordon, who had been with the boys on the recent expedition to Kwangara Island in the Western Pacific.
He smiled at Rick. "Didn't Zircon tell you the orders?"
"Yes, sir," Rick said. "I didn't want to come in. I just wondered if you'd do something for me."
Gordon consulted his watch. "Glad to, if it doesn't take more than fifteen minutes. I have something cooking in the annealer that will take just that long."
Rick was sorely tempted to ask questions, but he choked them back. "It won't take more than five." He handed the dog whistle to the scientist.
"Will you thread the inside of this so it will fit on an oxygen-bottle nozzle? Then charge the bottle with compressed air."
Gordon examined the whistle."An ultrasonic dog whistle, eh? All right, Rick. Wait here and I'll bring it out to you."
"What's ultrasonic?" Barby asked as the door closed.
"It's sound that is beyond the range of the human ear," Rick explained. "Birds and dogs, and lots of things can hear sounds that people can't. That's how the whistle works. It makes a sound just above our hearing range."
"I don't know why they couldn't make one we could hear as well as a dog," Barby said.
"It's mostly for people who have dogs in the city," Scotty told her. "They don't want to annoy their neighbors by blowing a loud whistle when they want to call their dogs, so they get these silent ones."
Rick's thoughts were far away. "I wonder," he mused absently. "Fifteen minutes in the annealing furnace, he said. What would he be working on?"
"Something made of glass," Scotty guessed. "That's what the annealing furnace is for."
"Maybe not. Maybe it's plastic," Rick hazarded. "Or maybe a special condenser for something. Dad originally got the furnace for making his own electronic condensers."
"Someday we'll know," Scotty said. "They'll get around to telling us."
"Yes, but by then all the excitement will be over."
Barby laughed gaily. "Now I know what's bothering you! It isn't the idea that Dad is keeping secrets. You're just afraid you're missing something!"
Rick grinned sheepishly. There was a lot to what Barby said. He hadn't had much excitement since the scientists had returned from the Pacific after exploring the sea bottom of Kwangara, one hundred fathoms down.
"Listen!" Scotty exclaimed suddenly.
From the other side of the island there was the sound of an engine turning over. Rick listened critically. It wasn't one of the Spindrift motorboats; he knew both of their engines. It must be the white cruiser.
"Dad's company has left," he said. "They didn't stay long this time."
"Long enough to get us locked out of the lab," Scotty said. "I'd give a pretty penny to find out who they are."
"And you're the boy who wasn't curious," Rick scoffed.
"I never said that, chum. I just said there wasn't any use trying to find out things until someone was ready to talk. I'm plenty curious."
"So am I," Barby agreed. "What if we went to see Dad now? We could ask him why we can't go into the lab."
"Nothing doing," Rick said flatly. "I tried to ask him about this business once, and he just said not to ask questions. He didn't even tell me why I wasn't supposed to ask 'em."
"Check," Scotty said. "We'll concentrate on helping Diz until they decide to let us in on whatever it is."
At that moment Professor Gordon opened the lab door and handed Rick the oxygen bottle with the whistle attached. "Here it is. Don't turn it on too loud, or you'll have every dog on the mainland heading this way--unless the thing explodes on you."
Rick accepted it with thanks, then tucked it under his arm. "Let's go back to the house and try it."
"If we can't hear it," Scotty asked, "how will we know if it's working?"
"That's easy," Barby said. "If Diz hears it, he'll come. If he doesn't hear it, he won't come."
"Even you should have been able to figure that out," Rick jibed.
"It takes a simple mind to figure out such simple things," Scotty said loftily. "I'm used to figuring out things that are hard."
They had reached the back door of the house. "Go ahead and try it, Rick," Barby said. "If it doesn't work, I'm going to go get Diz. He didn't show up at lunchtime and he didn't eat a thing this morning."
"All right." Rick examined the device to make sure the whistle was on tight. The oxygen bottle, charged now with compressed air, was a small metal container that terminated in a valve and nozzle. The dog whistle was screwed tightly to the nozzle. "Here goes," he said, and turned the valve.
At first there was only the sound of escaping air, then, with a loud pop the dog whistle split. Rick hastily shut off the air and regarded the cracked metal ruefully. "Too much pressure," he said. "The thing couldn't take it."
"Now what do we do?" Barby asked, disappointed.
"Take turns going to get Diz at mealtime," Scotty said. "When science fails, we have to go back to the old-fashioned way. We'll get Diz by ankle express."
"Science hasn't failed yet," Rick said. "I'll think of something."
"While you're thinking, I'll go get Diz." Barby started off down the path that led to the farm.
"Wait a minute," Scotty called. "I'll go with you. Coming, Rick?"
"Go ahead," Rick said. "I'll hang around there. Maybe I can dream up something."
He went back to his room while Barby and Scotty headed for the garden plot on the far side of the farm. There must be some way of making an ultrasonic whistle that Diz could hear.
If he only had another whistle � but maybe that wasn't necessary. Air forced through a hole made a noise. If the pressure were powerful enough, it would be a loud noise. Also, if the aperture were tiny, the sound would be high. He let the remaining air out of the oxygen bottle and examined it. The thing wasn't built for too high pressure. It wouldn't do. But how else could he get pressure?
He went to a closet and dragged out a box of odds and ends, prowling through it in search of an idea. He discarded an old transformer and similar junk. A regular police whistle turned up, but he discarded that, too. Little by little he emptied the box until only small things, like bits of wire and an accumulation of buttons, were left. Then, almost hidden under the rest, he saw a bright-red but of fluff. He took it out and looked at it, and an idea began to take form.
The fluff was the feathered tip of a tiny dart, designed to be shot from an air pistol. He couldn't remember how much pressure was built up in the pistol, but he knew it was a lot. He pushed the accumulated junk back in the box, then went to his dresser and found the pistol in the bottom drawer.
It was a simple device, built in the shape of an ordinary pistol. A lever pumped air into a false barrel directly under the barrel through which the dart traveled. By squeezing the trigger, the air was released and the dart shot out with terrific force.
Rick had stopped using the pistol for target practice because it wasn't accurate. First, though, he had tried to revamp it, threading the tip of the barrel to take an extension, on the theory that the longer the barrel, the greater the accuracy. It hadn't worked out.
He juggled the pistol in his hand and thought it over. Here was his compressed air supple. Now, if he could attach a whistle�His forehead wrinkled as he wrestled with the problem.
"I've got it," he said aloud. He could take a round piece of ordinary, rolled steel, drill it out and tap it so it would screw over the barrel, making a solid plug. Then, if he drilled a tiny hole, pin-point size, through the plug, it would be the only way for the air to escape. If the pinhole were small enough, he ought to get an ultrasonic sound, and a good loud one!
He was halfway down the stairs, carrying the pistol, when he remembered that the lab machine shop was barred to him. Besides, more than fifteen minutes had elapsed, and Gordon would be busy.
Rick went back into the house. He called the lab from the switchboard and asked for Gordon.
"Yes, Rick?"
"I'm sorry to bother you, sir. Could you do something else for me?"
"What is it?"
Rick outlined his needs. In a moment Gordon answered. "I haven't time, Rick, but Julius Weiss says he can do it for you if you hurry right over."
"Coming," Rick said, and hung up.
Professor Julius Weiss, a small, thin scientist who looked more like a bookkeeper than the astute mathematician that he was, stood in the doorway waiting. He examined the pistol, and his eyes twinkled at Rick from behind his glasses.
"Still inventing, eh? All right, I'll plug the opening for you. How big do you want the hole in the plug?"
"I don't know," Rick said. "How small can you make it?"
"Would a thousandth of an inch diameter do?"
Rick grinned. "It should."
"All right. It will take me about twenty minutes."
Rick watched the door close, then sat down on the lab steps. It was a funny feeling, being locked out.Plenty of secret experiments had gone on behind locked doors in the laboratory, but always before he had been in on them.
The gray stone building had been built by the government during the war, as an experimental laboratory under Hartson Brant's direction. The Spindrift scientists had conducted research into radar and other electronic fields. Then, with the war's end, the government had planned to tear down the lab buildings, but Hartson Brant and his fellow scientists had teamed up and won the Stoneridge prize for electronic development with the moon-rocket experiment, thus enabling the Spindrift group to buy the lab from the government and continue their research as an independent scientific foundation.
From the very beginning, Rick had worked in the lab, doing odd jobs and gradually acquiring the skill of a trained technician. Now, for reasons he could not fathom, he had to wait on the steps while one of his friends did a small machining job for him.
He would have liked to try pumping Zircon, Weiss, or Gordon, but his pride prevented him. They had excluded him. All right, he would stay excluded until they decided to tell him what it was all about.
In something less than twenty minutes, the door opened again. Julius Weiss sat down on the steps next to Rick, turning the air pistol over in his hands. The end of the barrel was now tightly plugged with shining steel, only an opening the size of a pin point providing a vent for the air.
"Interesting arrangement," Weiss said. "What are you going to do with it?"
Rick explained briefly about Dismal and his feud with the woodchuck. "I hope he'll be able to hear this," he finished.
Weiss polished his glasses thoughtfully. "I wonder. You'll get an ultrasonic sound, yes. But I'm afraid it will be well above Dismal's hearing range. It's true that dogs can hear higher sounds than humans, but even their range doesn't go very much beyond 25,000 cycles, if that far."
"How high do you think the sound from this will be, sir?" Rick asked.
Weiss shrugged. "There's no way of telling without measuring the wave length of the sound. I suggest that you try it. However, I'll be surprised if Dismal can hear it."
"I'll let you know how it works," Rick promised. "Thank you, sir."
He took the pistol and walked along the path that led to the farm. Barby and Scotty hadn't returned with Diz; he would have seen them from the lab steps if they had. He skirted the orchard, then hiked along the edge of the woods that covered most of the southern side of the island. The garden patch where the woodchuck had taken over was on the back side of the island.
He was almost there before he saw Barby and Scotty. They were hiding behind a large oak tree, peering out at something in the field.
Rick went into the woods and circled so that he came up behind them. He didn't know what they were watching, but he didn't want to upset their plans.
Scotty heard him and turned, a wide grin on his face. "Watch thins," he whispered. "But don't make any noise."
Rick looked out from behind the tree and took in the situation at a glance. Then he grinned, too. The woodchuck, a large, sleek specimen, was sitting up right in the very center of the lettuce patch. A mound of dirt told Rick that he was on the edge of an entrance to his burrow.
A few yards away, behind the woodchuck, a shaggy little dog was crouched, and he was worming his way toward the chuck, his belly close to the ground. Dismal was evidently planning to get within charging range before making a quick dash that would catch the woodchuck unawares � he hoped.
Rick, Barby, and Scotty watched, amused at Dismal's careful � but quiet useless � strategy. What Dismal didn't realize was that the woodchuck's eyes, set toward the sides of his head like a rabbit's, could see perfectly well what was going on.
The shaggy pup finally reached a point only half a dozen yards from the chuck and Rick say his legs gather under him. "He's going to charge," he whispered, just as Diz rushed.
The pup flew across the patch, allfour legs driving like pistons. The woodchuck sat perfectly still, head turned just the slightest bit. Then, just when it seemed the pup had him, he tumbled headlong into his hole. Dismal's teeth closed on air with an audible click. He let out a growl of frustrated anger, stumbled over the mound of dirt, and skidded nose first to a stop. The three watchers could restrain their laughter no longer. Diz sat up and listened, then ran toward them, his tail wagging sheepishly.
"Tough luck, old fellow," Rick greeted him. "You almost had that chuck for a minute, didn't you?"
"Almost is right." Scotty grinned. "Did you see that woodchuck dive?"
For the first time, Barby noticed the pistol in Rick's hand. "Are you going to shoot the woodchuck?" she asked.
Rick shook his head. "It's a new system I want to try." He explained the theory of its operation.
"Let's see if it works," Scotty suggested. "But don't get it too close to Diz. The sound might deafen him."
"Good idea," Rick agreed. He bent down and patted the shaggy pup. Dismal, pleased at the attention, rolled over and played dead, all four legs in the air. It was his only trick, and he performed it at the slightest nod from anyone.
"Wait here," Rick instructed him. "Sit down, pup."
Dismal obediently sat down, panting expectantly.
Rick, Scotty, and Barby walked away from him to a distance of about fifty feet, Rick meanwhile pumping the lever that charged the gun with compressed air.
"Far enough," Rick said. He aimed the air pistol at a point well over Dismal's head and pulled the trigger.
There was the faint hiss of escaping air, then Barby let out a sudden scream.
Dismal was shuddering as though from a physical impact. His head drooped and a quiver ran through him. Then he collapsed in a little furry heap on the ground and lay still!