"Yes, but he"ll know their game is up," said Harry. "Don"t you see, d.i.c.k?
He"ll tell them they"re suspected--and that"s all they"ll need in the way of warning. When men are doing anything as desperate as the sort of work they"re up to in that house, they take no more chances than they have to.
They"d be off at once, and start up somewhere else. We only stumbled on this by mere accident--they might be able to work for weeks if they were warned."
"Oh, I never thought of that! What are we to do, then?"
"I wish I knew whether anyone saw us from the house! If they didn"t--!
Well, we"ll have to risk that. d.i.c.k, do you see that house over there? It"s all boarded up--it must be empty."
"Yes, I see it." d.i.c.k caught Harry"s idea at once this time, and began measuring with his eye the distance to the little house of which Harry had spoken. "It"s all down hill--I think we could manage it all right."
"We"ll try it, anyhow," said Harry. "But first we"d better tie up his hands and feet. He"s too strong for the pair of us, I"m afraid, if he should come to."
Once that was done, they began to drag the spy toward the house. Half carrying, half pulling, they got him down the slope, and with a last great effort lifted him through a window, which, despoiled of gla.s.s, had been boarded up. They were as gentle as they could be, for the idea of hurting a helpless man, even though he was a spy, went against the grain. But--
"We can"t be too particular," said Harry. "And he brought it on himself.
I"m afraid he"ll have worse than this to face later on."
They dumped him through the window, from which they had taken the boards.
Then they made their own way inside, and Harry began to truss up the prisoner more scientifically. He understood the art of tying a man very well indeed, for one of the games of his old scout patrol had involved tying up one scout after another to see if they could free themselves. And when he had done, he stepped back with a smile of satisfaction.
"I don"t believe he"ll get himself free very soon," he said. "He"ll be lucky if that knock on the head keeps him unconscious for a long time, because he"ll wake up with a headache, and if he stays as he is, he won"t know how uncomfortable he is."
"Are we going to leave him like that, Harry?"
"We"ve got to, d.i.c.k. But he"ll be all right. I am going to telephone to Colonel Throckmorton and tell him to send here for him, but to do so at night, and so that no one will notice. He won"t starve or die of thirst. I can easily manage to describe this place so that whoever the colonel sends will find it. Come on!"
They went back to their cycles and rode on until they came to a place where they could telephone. Harry explained guardedly, and they went on.
CHAPTER VI
THE MYSTERY OF BRAY PARK
"I hope he"ll be all right," said d.i.c.k.
"They"ll find him, I"m sure," said Harry. "Even if they don"t, he"ll be all right for a few days--two or three, anyhow. A man can be very uncomfortable and miserable, and still not be in any danger. We don"t need half as much food as we eat, really. I"ve heard that lots of times."
They were riding along the line that Harry had marked on his map, and, a mile or two ahead, there was visible an old-fashioned house, with a tower projecting from its centre. From this, Harry had decided, they should be able to get the view they required and so locate the second heliographing station.
"How far away do you think it ought to be, Harry?" asked d.i.c.k.
"It"s very hard to tell, d.i.c.k. A first-cla.s.s heliograph is visible for a very long way, if the conditions are right. That is, if the sun is out and the ground is level. In South Africa, for instance, or in Egypt, it would work for nearly a hundred miles, or maybe even more. But here I should think eight or ten miles would be the limit. And it"s cloudy so often that it must be very uncertain."
"Why don"t they use flags, then?"
"The way we do in the scouts? Well, I guess that"s because the heliograph is so much more secret. You see, with the heliograph the flashes are centered. You"ve got to be almost on a direct line with them, or not more than fifty yards off the centre line, to see them at all, even a mile away.
But anyone can see flags, and read messages, unless they"re in code. And if these people are German spies, the code wouldn"t help them. Having it discovered that they were sending messages at all would spoil their plans."
"I see. Of course, though--that"s just what you said. It was really just by accident that we saw them flashing."
Then they came to the house where they expected to make their observation.
It was occupied by an old gentleman, who came out to see what was wanted and stood behind the servant who opened the door. At the sight of their uniforms he drew himself up very straight, and saluted. But, formal as he was, there was a smile in his eyes.
"Well, boys," he said, "what can I do for you? On His Majesty"s service, I suppose?"
"Yes, sir," said d.i.c.k. "We"d like to go up in your tower room, if you don"t mind."
"Scouting, eh?" said the old gentleman, mystified. "Do you expect to locate the enemy"s cavalry from my tower room? Well, well--up with you! You can do no harm."
d.i.c.k was inclined to resent the old gentleman"s failure to take them seriously, but Harry silenced his protest. As they went up the stairs he whispered: "It"s better for him to think that. We don"t want anyone to know what we"re doing, you know--not yet."
So they reached the tower room, and, just as Harry had antic.i.p.ated, got a wonderful view of the surrounding country. They found that the heliograph they had left behind was working feverishly and Harry took out a pencil and jotted down the symbols as they were flashed.
"It"s in code, of course," he said, "but maybe we"ll find someone who can decipher it--I know they have experts for that. It might come in handy to know what they were talking about."
"There"s the other station answering!" said d.i.c.k, excitedly, after a moment. "Isn"t it lucky that it"s such a fine day, Harry? See--there it is, over there!"
"Let me have the gla.s.ses," said Harry, taking the binoculars from d.i.c.k.
"Yes, you"re right! They"re on the top of a hill, just about where I thought we"d find them, too. Come on! We"ve got no time to waste. They"re a good seven miles from here, and we"ve a lot more to do yet."
Below stairs the old gentleman tried to stop them. He was very curious by this time, for he had been thinking about them and it had struck him that they were too much in earnest to simply be enjoying a lark. But Harry and d.i.c.k, while they met his questions politely, refused to enlighten him.
"I"m sorry, sir," said Harry, when the old gentleman pressed him too hard.
"But I really think we mustn"t tell you why we"re here. But if you would like to hear of it later, we"ll be glad to come to see you and explain everything."
"Bless my soul!" said the old man. "When I was a boy we didn"t think so much of ourselves, I can tell you! But then we didn"t have any Boy Scouts, either!"
It was hard to tell from his manner whether that was intended for a compliment or not. But they waited no longer. In a trice they were on their motorcycles and off again. And when they drew near to the hilltop whence the signals had come, Harry stopped. For a moment he looked puzzled, then he smiled.
"I think I"ve got it!" he said. "They"re clever enough to try to fool anyone who got on to their signalling. They would know what everyone would think--that they would be sending their messages to the East coast, because that is nearest to Germany. That"s why they put their first station here. I"ll bet they send the flashes zig-zagging all around, but that we"ll find they all get east gradually. Now we"ll circle around this one until we find out in what direction it is flashing, then we"ll know what line we must follow. After that all we"ve got to do is to follow the line to some high hill or building, and we"ll pick up the next station."
Their eyes were more accustomed to the work now, and they wasted very little time. This time, just as Harry had guessed, the flashes were being sent due east, and judging from the first case that the next station would be less than ten miles away, he decided to ride straight on for about that distance. He had a road map, and found that they could follow a straight line, except for one break. They did not go near the hilltop at all.
"I"d like to know what they"re doing there," said d.i.c.k.
"So would I, but it"s open country, and they"re probably keeping a close lookout. They"re really safer doing that in the open than on the roof of a house, out here in the country."
"Because they can hide the heliograph? It"s portable, isn"t it?"
"Yes. They could stow it away in a minute, if they were alarmed. I fancy we"ll find them using hilltops now as much as they can."
"Harry, I"ve just thought of something. If they"ve planned so carefully as this, wouldn"t they be likely to have country places, where they"d be less likely to be disturbed?"
"Yes, they would. You"re right, d.i.c.k. Especially as we get further and further away from London. I suppose there must be plenty of places a German could buy or lease."