"What in the world are you doing out here?" Higginbotham demanded, sharply.
"Why, we told you we lived near here. We had flown to Mineola and then motored to the city. And we were just flying home when we saw you fall, and came over to do what we could."
"Oh."
Higginbotham stared from one to the other. Had he seen them pursue him and spy on him as he visited the schooner? That was the question each boy asked himself. Apparently, he had not done so, for his next question was:
"Do you fly around here often in your plane?"
Frank took a hand in the conversation. If big Bob were left to carry on alone, he might blunderingly give this man an inkling of what the boys knew or suspected about their mysterious neighbors. Frank felt that his chill of suspicion, experienced when he encountered Higginbotham in New York, was being justified. Decidedly, this man must be in with the mysterious inhabitant of the old Brownell place.
Equally certain was it that he had lied in stating he did not know the name of the man who had bought the property.
"Oh," said Frank, "we haven"t had the plane out for weeks until a day or two ago, when we made a trial spin, and again to-day. We"ve been busy for a month overhauling it."
That, thought Frank, ought to stave off Higginbotham"s suspicions.
Evidently, the other was feeling around to learn whether they had flown sufficiently of late to have spied out the secret radio plant or seen the radio-controlled plane in operation.
"And I"ll bet," Frank said himself, "that it is a complete surprise to him to find there is a plane in his neighborhood. Probably, he thought he could operate without fear of discovery in this out-of-the-way neighborhood, and it"s a shock to him to find we are here."
Some such thoughts were pa.s.sing through Higginbotham"s mind. How could he get rid of these boys without disclosing to them that his was a radio-controlled plane?
"I"m very much obliged to you, gentlemen," he said, smoothly, "for coming to my aid. As it is, however, I do not need help. This is a plane of my own design, I may as well state, for I can see its surprising lines have aroused your curiosity. I would prefer that you do not come any closer but that, on the other hand, you would leave me now. I want to make some minor repairs, and then I shall be able to fly again."
"Very well, sir," answered Bob composedly, climbing back from the fusilage to his seat in the pit. "We don"t want to annoy you. Good day."
With that, Frank swung clear, the propeller to which Bob had given a twist began anew to revolve, the plane taxied in a circle, then rose and started for the sh.o.r.e.
"We certainly surprised him," chuckled Jack. "He didn"t know what to say to us. In his excitement and his fear of discovery of some secret or other, he acted in a way to arouse suspicion, not dispel it. Well, Frank, you win the gold medal. Your hunch about Higginbotham being untrustworthy certainly seems to have some foundation."
"I"ll say so, too," agreed Bob. "But what do you imagine happened to him?"
Bob sat with the gla.s.ses trained backwards to where the little plane still rode the sea.
"That"s easy," answered Jack. "Something went wrong at the secret radio plant and the continuity of the dash which provides the juice for the plane"s motor was broken. That"s the only way I can figure it.
I say. Let"s tune up to 1,375 meters, and see whether that continuous dash is sounding."
"It"s not there," Bob announced presently. "Not a sound in the receivers. Neither does the plane show any signs of motion. Look here.
Suppose that whatever has happened at that fellow"s radio plant cannot be fixed up for a long period, what will Higginbotham do? Ought we to go away and leave him?"
"Well," said Jack, doubtfully, "it does look heartless. He"s four or five miles from sh.o.r.e. Of course, we might shoot him a continuous dash from our own radio plant."
"Zowie," shrieked Bob, s.n.a.t.c.hing the receiver from his head, and twisting the controls at the same time, in order to reduce from the 1,375-meter wave length. "There"s his power. No need for us to worry now. Oh, boy, but wasn"t that a blast in the ear?"
Ruefully, he rubbed his tingling ears. Jack was doing the same. Poor Frank, whose eardrums had been subjected to the same shock, also had taken a hand from the levers at the same time and s.n.a.t.c.hed off his headpiece.
"She"s rising now," cried Bob.
Without his headpiece, Frank could not hear the words and kept his eyes to the fore, as he swung now above the line of the sh.o.r.e. Jack, however, also was straining his eyes to the rear, and he s.n.a.t.c.hed the gla.s.ses from Bob and trained them on the plane.
True enough, Higginbotham was rising.
CHAPTER VII
A CALL FROM HEADQUARTERS
It was not yet five o"clock when, the airplane safely stowed away and the doors of the hangar closed and locked, the boys once more stood on the skidway.
"What say to a plunge before we go up to the house?" proposed Frank.
"There"s n.o.body to see us. We can strip down at the beach, splash around for ten minutes, and then head home. It"s a hot, sticky day and that trip to the city left me with the feeling that I wanted to wash something away."
The others agreed to the proposal and they started making their way to the sh.o.r.e, discussing the latest turn of events on the way.
"It certainly looks as if your hunch about Higginbotham, when we met him in his office, was justified," said Jack, clapping Frank on the shoulder.
"The boy"s a wonder," agreed Bob. Then, more seriously, he added:
"But, I say. Higginbotham isn"t the man who flew the radio-controlled plane before. I mean the fellow whose tracks I found in the sand. That chap was peg-legged."
"That"s right," agreed Jack. "And where does Higginbotham figure in this matter, anyhow? It"s some mystery."
"Well, let"s see what we do know so far," suggested Frank. "It"s little enough that we have found out. But I like mysteries. First of all, Bob finds a secret radio plant, and----"
"No," interrupted Jack. "First of all, I discover interference in the receivers at a 1,375-meter wave length."
"Yes, that"s right," said Frank. "Well, second is Bob"s find of the radio plant to which he is led by tracks in the sand made by a peg-legged man. Look here. Bob thought at the time that man had arrived in a boat. He saw marks on the sand indicating a boat had been pulled up on the sh.o.r.e. Might not that have been the indentation made by the radio plane?"
"Just what I was thinking to myself a minute ago," said Bob.
"Anyhow," continued Frank, "we then discovered the radio plane in Starfish Cove. From Uncle George we learned a mysterious stranger had recently bought the Brownell place, the "haunted house," and had built a fence about the property and set armed guards to keep out intruders. The plot was thickening all the time."
By now the boys had reached the sh.o.r.e and well above the tide mark they began to strip, dropping their clothes in heaps. Frank continued talking as he shed his garments:
"So we decided to go up to the city and ask Mr. McKay who it was had taken the Brownell place. Instead of Mr. McKay we found his secretary, Higginbotham, who professed to know nothing about the matter. Yet, when we arrive down here, we find Higginbotham in the radio plane, visiting a schooner well off sh.o.r.e.
"Say, fellows," he added, as having dropped the last article of clothing, he stood prepared to plunge in; "that man Higginbotham must have left his office immediately after we interviewed him, and probably came down by motor car. We spent two or three hours longer in the city, which gave him the chance to beat us. Now what brought him down here?"
"Search me," said Bob. "There may be a big liquor plot, and he may be in it. Probably, is. Perhaps he was alarmed at our inquiries and hurried down to keep things quiet for a while."
"That"s just what he did, Bob, I do believe," said Jack, approvingly.
"I believe you"ve hit it."
"Oh, well, come on," said Bob. "Let"s have this plunge."
Scooping up two handsful of wet sand he flung it at his companions.