The thing was moving toward them, flapping!
Resisting an impulse to run, the Hardys closed in. They clutched at the specter. Joe gave a chuckle of relief as he felt the wire framework underneath. It was covered with some kind of synthetic cloth, which evidently had been dipped in white phosphorescent dye.
“Just a pop-up scarecrow, Frank! We must have stepped on the release mechanism back there.”
“Right, Joe. And look at the wheels. The breeze blew it toward us!”
They went on. In the shadow of a tree they paused and looked up at the lighted window. Shelves with bottles and test tubes, and some electrical apparatus, could be seen.
“A laboratory!” Joe murmured.
Behind the shaded windows on the ground floor a radio was blaring dance music.
Suddenly a man moved into view at the upper-floor window. Bald and bespectacled, he was holding an open book in one hand.
“There he is!” Frank whispered.
“That's Darrow, all right,” Joe agreed. “If only we could talk to him!”
“Fat chance with Strang and his gang around. Anyhow, we've seen all we need to. Let's go home and wait for Dad.”
Turning, the brothers started back across the grounds to their car. Halfway down the slope, they heard the screams and the choking voice again.
“Hold it, Joe,” Frank hissed. “That tiled floor's around here somewhere. Did you notice that we always hear the screams near here?”
The boys shone their flashlights carefully about the ground. Suddenly Joe's beam disclosed a small metal object sticking up from the grass.
“I'll bet that's it, Frank! Must be some kind of sensorâmaybe infraredâthat triggers off a tape recording when anyone comes near.”
Joe moved closer to examine it. Again the voice shrieked! Startled, Joe backed off hastily and his foot struck a rock.
Frank gave a cry of dismay as the ground gave way under his feet. Down he plunged!
“The tunnel exit!” Joe exclaimed. “My foot hit a rockâsame thing that happened last night. That must be what opens it from the outside.”
“Right. And look at all this sod and brush that fell in with meâthey do camouflage the tiled floor.” Frank shone his flashlight into the tunnel. “Wonder if we could get into the house this way, past Strang and his henchmen, and talk to Professor Darrow?”
Joe leaped down beside Frank. “I'm game! Let's find out where the tunnel leads!”
CHAPTER XVIII
A Strange Machine
FRANK had been only half serious when he spoke of trying to enter the house through the tunneL But Joe's excitement communicated itself to him. This might be a chance to get information or a clue that would break the case!
“Okay. Let's take a look.”
They started into the tunnel, one behind the other. Frank led the way, probing the darkness with the yellow beam of his flashlight.
“Watch that intercom!” Joe warned. “We don't want another chat with Waxie's pal!”
The brick-walled passageway went on for hundreds of feet. The boys came at last to a door. It had a lock but opened freely when Frank tried the knob. “It must unlock automatically when the tiled floor opens,” he whispered.
“In that case, why the intercom?”
Frank shrugged. “Someone might want to hide in the tunnel but still be able to communicate with the house. Or maybe they post a lookout at the tunnel exit sometimes and have him report back by phone.”
The boys played their flashlights around. “We must be in the basement of the mansion,” Joe murmured.
The huge, cement-floored area was dank and musty. There was a coalbin, a grimy-looking, cobwebbed furnace, and an air-conditioning unit that looked brand new. Far at the rear was a flight of stairs leading upward.
Frank asked his brother, “Should we risk it? Or turn back?”
“Don't be silly! We're going to talk to Professor Darrow, remember?”
The boys walked cautiously toward the stairway and tiptoed up. They found that the first flight ended at the kitchen of the sprawling mansion. From here another flight led upward. The stairs creaked under the boys' tread, but fortunately the radio music racketing in the ground-floor front rooms covered their noise.
Reaching the upper floor, the boys went along a corridor toward the front of the house. The hallway twisted and turned as if the mansion had been designed with an eccentric floor plan. After passing several doors, the Hardys stopped at one which showed light underneath.
“This must be the laboratory,” Frank whispered.
Joe held up crossed fingers. “Okay. Let's find out.”
Frank opened the door. Professor Darrow was holding a test tube of colored liquid up to the light. He turned as the boys enteredâand gave such a violent start that the liquid splashed on his workbench!
“Professor Darrowâ?” Frank inquired. Joe closed the door softly behind them.
The scientist's hand trembled as he placed the test tube in a rack. He stared at the Hardys through his steel-rimmed eyeglasses and his eyes were full of fear.
“Who are you? What do you want?” he blurted out in a shrill, staccato voice.
The muffled strains of the radio music could be heard through the floor.
“We're Frank and Joe Hardy, sir,” Frank began. “Our father is Fenton Hardy.”
He assumed the name would be familiar to a crime-detection expert. But Darrow glared at them, giving no sign of recognition.
“Fenton Hardyâthe private investigator,” Joe emphasized. “Maybe you've heard of him.”
“Maybe.” The scientist's eyes bored through the boys. He wore a white lab coat and his wispy fringe of gray hair frothed out wildly around his narrow skull. “Why did you come here?”
“Dean Gibbs of Western State asked us to locate you andâ” Frank started to explain.
“He would! You've come here to spy on me!”
“That's not true!” Frank exclaimed.
“The dean wired us on behalf of your sister,” Joe put in hastily. “She'd like you to get in touch with her. She's probably worried because she hasn't heard fromâ”
Joe broke off suddenly as he noticed the professor's hand inching toward a strange device on his workbench. It looked somewhat like a round, portable electric heater.
“Look out, Frank!”
Joe leaped clear in the nick of time as Professor Darrow snatched up the device. But Frank did not react fast enough. A dazzle of light flared from the machine. Instantly Frank stiffened and froze statuelike.
He had blacked out!
An electric cord ran from the machine to a wall socket. Joe yanked the plug before Darrow could aim the device at him.
“Help! Help!” the professor shouted.
Joe glanced around frantically. The radio music from below had stopped. A moment later came the sound of feet pounding up the stairs!
“Strang and his boys!” Joe thought. “I'll have to duck fast! But where?”
Suddenly Darrow lunged at him and tried to pin the boy's arms. Joe wrenched free and gave the professor a hard shove that sent him reeling backward. Darrow crashed into a corner of the workbench and went down in a cascade of glass tubing, retorts, and other laboratory apparatus.
Like a flash, Joe darted out through a doorway that led to an adjoining room. The door slammed behind him just as Strang and several henchmen came surging into the laboratory.
“That way!” Darrow shrilled, pointing in the direction of Joe's flight. “Through that door!”
The gang rushed through a maze of connecting rooms. Joe, concealed behind the heavy, dark-red window drapes in the room next to the lab, could hear Strang barking out orders.
A moment later the master jewel thief strode past Joe's hiding place on his way back to the laboratory. Through the open doorway, Joe heard him talking to the professor.
“Yes, I know the boy. Recognized him at once,” came Strang's voice, evidently referring to Frank. “He and his brother are the sons of a clever spy who must have been sent to Bayport purposely to steal your invention.”
“Just what I feared!” Darrow replied. “Then it's not true that they're connected in any way with Fenton Hardy?”
“Certainly not! In fact, Hardy's now on my payroll, working undercover to safeguard your research.” Strang's voice became firm and persuasive. “Don't worry, Professor! My men are bound to catch the other boy. Then we'll hand them both over to the FBI.”
“Frank, look out!” Joe yelled
“I certainly hope you're right!” Darrow sighed heavily. “First the university authorities and jealous colleagues blocked my research grant at school! And now spies hounding me!”
“By the way,” Joe heard Strang ask, “how deeply did you black this kid out?”
“Just a light dose. But it should hold him long enough toâ”
A loud alarm bell rang on the first floor, cutting short the professor's words. Both Strang and Darrow dashed from the lab.
Joe waited until he heard their steps fading down the stairs. Then he burst from the drapes and rushed into the laboratory. Frank was still rigid. Joe filled a beaker with cold water from the workbench sink faucet and flung it in his brother's face. Frank seemed to shudder.
“Frank! ... Frank, can you hear me?”
Joe shook his brother and gave him several light slaps. Gradually Frank came out of the trance but appeared to have no recollection of what had happened. Joe explained hastily, adding, “Strang has the prof convinced that he's surrounded by spiesâincluding us. An alarm just went off downstairs, and they've gone to investigate.”
Frank was still a bit dazed. “I must have been blacked out by the same device used in the jewel thefts, Joel”
“Sure, and Darrow thinks we came to steal it. We must find a way out of this place!”
“Wait a second, Joe! That alarm you mentioned could have been Dad coming hereâmaybe even the police!”
“Right,” Joe agreed. From the sounds he had heard, he knew there must be a front stairway. The Hardys soon found it and strained to hear what was going on below.
“Here they come now!”. Strang was saying. ”Looks as though they've nabbed whoever triggered the alarm!”
Frank and Joe leaned around the corner of the stair well and peered down into the front hall. Strang was at the front door with Professor Darrow. Presently three of Strang's henchmen came in, prodding a burly prisoner at the point of a gun. Their captive had crew-cut hair and wore a gaudy plaid sport coat.
“Duke Makin!” Joe whispered in amazement.
“No sign of that kid who got away, boss,” the gunman reported. “But we caught Makin here snooping around outside.”
“Good work, Barney!” Strang said approvingly.
“Barney's the man who was with Jack Wayne at Tigers' Bight!” Frank murmured in Joe's ear.
Duke Makin looked self-assured, which appeared to infuriate Strang.
“I warned you once before, Makin, to keep out of my hair!” the jewel thief rasped.
Makin laughed contemptuously. “And I told you, Strang, that I'm dealing myself in on this jewel racket of yours.”
“You're not muscling in on anything, Makin, except big trouble.”
Again Makin laughed. “You're the one who's got trouble. After you learned Fenton Hardy was on your case, a pal of mine in Chicago found out he was there. I asked my pal to tip off Hardy about the Haley Building job. How did I know about it? I overheard you blokes talking after you cased Tiffman's office. And there'll be more tip-offs if I don't collect a share on every jewel haul you make from now on. I want to know what your blackout gimmick is, too.”
“What's he talking about?” Professor Darrow asked Strang. “What does he mean by âevery jewel haul you make'?”
“Get back up to your lab, Professor!” Strang ordered roughly. “This man is another foreign agentâhe's simply trying to pull the wool over your eyes. I'll handle him!”
Darrow obeyed meekly, but he looked bewildered as he started up the steps. Frank and Joe shrank back into the shadows. Darrow reached the top of the stairs and turned toward his laboratory without noticing them.
Meanwhile, Makin had resumed his sneering argument with Strang. “I mean business!”
“Shut up!” Strang exploded. “We know you conked Waxie at the airport and swiped those amethysts from my carâbut it's the last trick you'll pull, Makin! Take him to our âguest room,' boys. I'll attend to him later, after we find the other kid!”
They herded Makin off toward the rear of the house. Frank and Joe tiptoed cautiously down the stairs, hoping to make a break through the front door.