"We"ll go straight to headquarters for our information," declared Frank. "We"ll make another search of the fellow"s house."
They realized fully the danger they were likely to run into. To offset any worry on the part of their father, they left a note for him with instructions to send the police to the Vilnoff place as well as to the cabin in the woods, should the boys fail to return home by midnight. Frank sketched a map giving complete directions for reaching the shack.
They set out after dark and made their approach to the Vilnoff house very cautiously. For several minutes they stood outside the fence, watching the place until they were convinced that no one was lurking in the grounds.
"We must learn more about what"s going on in that cellar," Frank decided. "And we just can"t afford to be caught prowling around, either."
They crossed the lawn safely, flitting from tree to tree and from bush to bush until at last they were in the deep shadows at one side of the house.
"The cellar light is on," whispered Joe.
They could see the yellow rectangle of illumination beyond a clump of barberry. Quietly they crept forward to the window.
Here they met with a disappointment. The cas.e.m.e.nt had been covered on the inside with a coating of cream coloured paint. Nothing of the bas.e.m.e.nt beyond was visible.
For a while the boys crouched, listening intently. They could hear a constant whirr of machinery and an occasional clank-clank of metal on metal, followed by the rending noise of a saw cutting through iron. Once in a while someone coughed, then walked around.
Frank tried the side of the window. It was loose.
"Maybe I can move it out enough to see what is going on in there," he whispered.
He again tugged gently at the side of the cas.e.m.e.nt and it gave slightly. Another tug, and the window slipped in Frank"s grasp. To his horror, one elbow crashed completely through the gla.s.s.
The shattering of the pane made a tremendous racket in the stillness of the night. To make matters worse, the frame slipped through Frank"s fingers, causing the whole sash to tumble into the cellar. It fell on the concrete floor of the bas.e.m.e.nt with a splintering crash.
Through the opening the boys could see someone 122 run across the floor of the bas.e.m.e.nt to a door at the back of the room. They recognised the figure immediately.
The man was Vilnoff!
For an instant the man"s face was clearly revealed to them in the electric light. Then he pulled open the door and vanished.
"After him!"
Frank was scrambling through the open window. He dropped onto the concrete floor and rushed in pursuit. Joe was close at his brother"s heels.
The exit through which Vilnoff had disappeared refused to open. The wily fellow had locked it on the other side.
"Try the upstairs way!" suggested Joe.
The boys had now thrown caution to the winds. Frank wheeled around and ran up the bas.e.m.e.nt stairs. He wrenched open the door at the top of the landing, and the two lads stepped through.
They found themselves in the kitchen of the house. Not a sound was to be heard from any part of the building. Vilnoff was nowhere to be seen.
As the Hardys stood there, undecided, the roar of a motor outside echoed suddenly.
The boys ran to the back door. Through the gla.s.s panel they could see a car leaving the garage.
Frank and Joe were out of the house in a twinkling. By the time they had leaped from the porch the automobile was speeding down a lane toward the rear of the estate.
"Vilnoff must be in that car!" exclaimed Frank in disappointment.
123.
"But how did he ever get to the garage?"
They went over to the small building to investigate. Their flashlights revealed a trap-door in the floor of the empty structure. Joe bent down and raised it, and as he did so the boys saw a flight of steps that led to a pa.s.sage below.
Frank descended the stairs to find an underground tunnel leading from the garage to the bas.e.m.e.nt of VilnofFs house. At the end of the pa.s.sage he noticed a closed door; the key was still in the lock. The lad opened it and discovered, as he had suspected, that it led to the cellar of the house and was the very way by which the owner had fled when the Hardy boys had entered his workshop.
"I guess Vilnoflf has escaped," said Joe, who had followed Frank into the bas.e.m.e.nt.
"There doesn"t seem to be anyone else around the place, so we can have a good look at this shop of his."
On a nearby bench lay a sheaf of blue-prints. The boys examined them, and on the first set of plans they read: "SUPER AERIAL BOMB." On another was inscribed, "MODEL B, SPECIAL MACHINE GUN." On a third, "SECRET-LIGHTWEIGHT TORPEDO FOR SUBMARINE USE."
The boys were astounded, and became even more so when a search of the bas.e.m.e.nt revealed supplies of nitroglycerine, T.N.T., dynamite, gunpowder, gun-cotton, caps, fuses-enough deadly explosives to lay Bayport in ruins for blocks around. There was a model of a strange new type of machine gun under a tarpaulin 124 in a corner. On the work-bench was the sh.e.l.l of a bomb.
"So that"s the secret of Vilnoff"s place 1" exclaimed Frank. "Inventions of warfare!"
"This is a matter for the police. No wonder the man ran away."
The boys went upstairs, and searched the house high and low but the place was deserted. There was no trace of the butler, the gardener, or the chauffeur.
Joe went to the telephone and called Bayport police headquarters. He gave his name and then said: "I think you had better send a couple of men down to stand guard over the Vilnoff residence tonight. Frank and I have made some mighty queer discoveries here."
"What"s up?" asked the desk sergeant who had answered the phone.
"We"ve found a bas.e.m.e.nt full of explosives. It looks as if Vilnoff has been using the house for inventing instruments of warfare."
"Whew!" exclaimed the officer in astonishment. "I"ll send some men up there right away."
Joe put down the telephone.
"What"s next?" he asked Frank.
"We must find Vilnoff and his cronies. I have a notion that the cabin in the clearing may be his hiding place."
"Shall we go there tonight?"
"Why not? That fellow may quit the country altogether, now that he knows the secret of his place has been discovered."
Joe agreed that this plan of procedure was entirely 125.
probable. Quick action was necessary. Although the Hardy boys could hardly realize as yet the tremendous importance of the secret upon which they had stumbled, they knew that Vilnoff"s possible presence at the cabin in the clearing now took on a more sinister aspect.
"I think that place hides something a lot more important than the temporary home of a stolen horse," declared Frank. "Those tree signals have been put in place for a definite purpose. I think they were used when we were there to warn the guards of our approach."
"Well," said Joe, "with what Dad told us, and after seeing those cases unloaded from the launch on the river, I suspect munitions."
"We"ll have to prove that before we report it," returned Frank.
"You"re right," agreed his brother. "We won"t take any unnecessary risks, but we could spy once again in the forbidden territory."
"Sure. Then bring in the police. We can"t let Vilnoff get away with his queer schemes any longer."
The boys did not want to leave the man"s Bayport house until the police should arrive.
They were disappointed because Vilnoff had tricked them and escaped through the secret pa.s.sageway, which doubtless had been prepared for just such an emergency.
"Remember what Dad said at breakfast one morning when we were talking about mysteries?" asked Joe. "He told us it was thought that certain foreigners were buying munitions and concealing them in this country. I"ll bet that"s what Vilnoff has been mixed up in."
126.
"Probably he"s the ringleader," Frank remarked.
Then a surprising thing happened. Every light in the house went out. Just as they did so the burglar alarm began ringing shrilly.
CHAPTER XVII.
THE STRANGE MESSAGE.
while the bell was still ringing the Hardys heard heavy footsteps in the front hall. Then a gruff voice called out: "Hj, there! What"s going on?"
The boys switched on their flashlights and went to the front door. Two police officers were standing there. The alarm was still screeching madly.
The authorities had found the door unlocked and had entered without knocking. At the same moment the burglar alarm had been set into action. Frank reached out for the switch that controlled the signal and in a second the uproar ceased. Simultaneously the lights went on again.
"What"s the matter? Who turned out the lights?" demanded one of the policemen. "What kind of a dump is this, anyway? The minute we opened the door they all went out and that bell began clangin" like mad."
"I guess some mechanism connected with the burglar alarm did it," said Frank.
"Well, what"s all the trouble?" demanded the leader of the pair. "Let"s have a look at this bas.e.m.e.nt the sergeant was talking about."
Frank and Joe guided the men down to the cellar 127.
128 and showed them the plans and models they had discovered. They explained that they had been suspicious of Vilnoff, and had surprised him at work when, to all intents and purposes, he was supposed to be on his way to Europe. They related how he had escaped to the garage by the underground pa.s.sage.
The policemen were impressed.
"You can just bet we"ll guard this stuff. If anybody should get in here and touch any of it off it would blow half the town to pieces."
Frank and Joe said nothing of their own plans for going to the hide-out in the woods.
Now that the house was under guard, with the policemen in readiness to apprehend Vilnoff and question him should he be unwary enough to return, they felt at liberty to leave and continue their own investigations.
When they left they held a council of war, discussing what their next move should be.
Frank was all for setting out for the cabin in the woods at once, but another idea had occurred to Joe in the meantime.
"I think that mechanical tree gives them warning when anyone goes on the road near the place," he said. "Who knows but that Vilnoff may have some guards here now, and we may be followed. I"d suggest that we try to throw them off the scent."
"How?"
"You take the Sleuth Sleuth up the river and wait for me in the inlet near the place where we up the river and wait for me in the inlet near the place where we were stalled when we saw the men unloading the boxes from the launch."
"And what will you dor"
"I"ll take the car and drive out to that petrol station. I"ll pretend something has gone wrong with the 129.
machine. I"ll ask Gus for permission to use the telephone. I"ll call you, supposedly, giving the impression that you are at home in Bayport."
"I get it," said Frank. "It looks as if Gus and Pete have some connection with Vilnoff. You may learn a few things at the petrol station in the bargain."
"Perhaps. I"ll merely use the telephone and say I"ve been delayed coming home. Then, after I leave I"ll drive around to the inlet by one of the old roads back of the airport."
The Hardy boys parted company outside the Vilnoff place and went their separate ways, Frank toward the boat-house where he tuned up the Sleuth Sleuth for the night journey on the river, for the night journey on the river, his brother toward their car, which he guided to the service station outside the city limits.
Joe"s journey did not take very long, but on the way he kept thinking about Gus. He was fully convinced that the proprietor and Pete, the truck-driver, knew more about Vilnoff and his mysterious activities than either of them would care to admit. In the back of the boy"s mind was the hope that his visit to the service station might result in some clues of real value.
When the lights of the place appeared in view Joe slowed down and brought his car to a stop about a hundred feet from one of the petrol tanks. Then he got out, lifted the hood of the roadster, and quickly disconnected a wire leading to the battery.
In a moment he walked toward the building and was just about to open the door, when he heard the ringing of a telephone inside. Soon he heard the gruff voice of Gus calling: 130 "h.e.l.lo!"
Then came a pause.
"h.e.l.lo yourself," said the proprietor.
Another pause. Then the man remarked: "Shake hands."
Joe heard a rattle as the receiver was put back into pbce.
The lad could not make head nor tailof the extraordinary conversation. "Shake hands!"
What did it mean?
It occurred to him that Gus might have been speaking in accordance with a code previously arranged between himself and the person who had telephoned. This conviction only served to increase his suspicion that the proprietor and his petrol station were not doing just the kind of business they appeared to be.
Joe waited a few moments, then banged noisily on the door. It was opened by Gus, who was in his shirtsleeves. The man gave an exclamation of surprise when he recognized Joe.
"h.e.l.lo," he said in a surly tone. "What do you want?"
"Something"s wrong with my car," returned the lad. "I"d like to use your telephone, if you don"t mind."