THE CIPHER
"What happened to you?" asked Jack and Dick in chorus.
Swiftly Harry explained. He told of his arrest as a spy and of his
escape. And when he mentioned the part that Ernest Graves had played in
the affair, Jack and Dick looked at one another.
"We were afraid of something like that, said Jack. "Harry, we've found
out a lot of things, and we don't know what they mean! We're sure
something dreadful is going to happen tonight. And we're sure, too, that
Bray Park is going to be the centre of the trouble."
"Tell me what you know," said Harry, crisply. "Then we'll put two and
two together. I say, Jack, we don't want to be seen, you know. Isn't
there some side road that doesn't lead anywhere, where I can run in with
the car while we talk?"
"Yes. There's a place about a quarter of a mile further on that will do
splendidly," he replied.
"All right. Lead the way! Tell me when we come to it. I've just thought
of something else I ought to never have forgotten. At least, I thought
of it when I took the things out of my pockets while I was changing my
clothes."
They soon came to the turning Jack had thought of, and a run of a few
hundred yards took them entirely out of sight of the main road, and to a
place where they were able to feel fairly sure of not being molested.
Then they exchanged stories. Harry told his first. Then he heard of
Dick's escape, and of his meeting with Jack. He nodded at the story they
had heard from Graffer Hodge.
"That accounts for how Graves knew," he said, with much satisfaction.
"What happened then?"
When he heard of how they had thought too late of calling Colonel
Throckmorton by telephone he sighed.
"If you'd only got that message through before Graves did his work!" he
said. "He'd have had to believe you then, of course. How unlucky!"
"I know," said Jack. "We were frightfully sorry. And then we went out to
find where the wire was cut, and then got Dick. But I got away, and I
managed to stay fairly close to them. I followed them when they left
Dick in a little stone house, as a prisoner, and I heard this--I heard
them talking about getting a big supply of petrol. Now what on earth do
they want petrol for? They said there would still be plenty left for the
automobiles--and then that they wouldn't need the cars any more, anyhow!
What on earth do you make of that, Harry?"
"Tell me the rest, then I'll tell you what I think," said Harry. "How
did you get Dick out? And did you hear them saying anything that sounded
as if it might be useful, Dick?"
"That was fine work!" he said, when he had heard a description of Dick's
rescue. "Jack, you seem to be around every time one of us gets into
trouble and needs help!"
Then Dick told of the things he had overheard--the mysterious references
to Von Wedel and to things that were to be done to the barracks at
Ealing and Houndsditch. Harry got out a pencil and paper then, and made
a careful note of every name that Dick mentioned. Then he took a paper
from his pocket.
"Remember this, Dick?" he asked. "It's the thing I spoke of that I
forgot until I came across it in my pocket this morning."
"What is it, Harry?"
"Don't you remember what we watched them heliographing some messages,
and put down the Morse signs? Here they are. Now the thing to do is to
see if we can't work out the meaning of the code. If it's a code that
uses words for phrases we've probably stuck, but I think its more likely
to depend on inversions."
"What do you mean, Harry?" asked Jack. "I'm sorry I don't know anything
about codes and ciphers."
"Why, there are two main sorts of codes, Jack, and, of course, thousands
of variations of each of those principal kinds. In one kind the idea is
to save words--in telegraphing or cabling. So the things that are likely
to be said are represented by one word. For instance Coal, in a mining
code, might mean 'struck vein at two hundred feet level.' In the other
sort of code, the letters are changed. That is done in all sorts of
ways, and there are various tricks. The way to get at nearly all of them
is to find out which letter or number or symbol is used most often, and
to remember that in an ordinary letter E will appear almost twice as
often as any other letter--in English, that is."
"But won't this be in German?"
"Yes. That's just why I wanted those names Dick heard. They are likely
to appear in any message that was sent. So, if we can find words that
correspond in length to those, we may be able to work it out. Here goes,
anyhow!"
For a long time Harry puzzled over the message. He transcribed the Morse
symbols first into English letters and found they made a hopeless and
confused jumble, as he had expected. The key to the letter E was
useless, as he had also expected. But finally, by making himself think
in German, he began to see a light ahead. And after an hour's hard work
he gave a cry of exultation.
"I believe I've got it!" he cried. "Listen and see if this doesn't sound
reasonable!"
"Go ahead!" said Jack and Dick, eagerly.
"Here it is," said Harry. "Petrol just arranged. Supply on way. Reach
Bray Friday. Von Wedel may come. Red light markers arranged. Ealing
Houndsditch Buckingham Admiralty War Office. Closing."
They stared at him, mystified.
"I suppose it does make sense," said Dick. "But what on earth does it
mean, Harry?
"Oh, can't you see?" cried Harry. "Von Wedel is a commander of some
sort--that's plain, isn't it? And he's to carry out a raid, destroying
or attacking the places that are mentioned! How can he do that? He can't
be a naval commander. He can't be going to lead troops, because we know
they can't land. Then how can he get here? And why should he need
petrol?"
They stared at him blankly. Then, suddenly, Dick understood.
"He'll come through the air!" he cried.
"Yes, in one of their big Zeppelins!" said Harry. "I suppose she has
been cruising off the coast. She's served as a wireless relay station,
too. The plant here at Bray Park could reach her, and she could relay
the message on across the North Sea, to Helgoland or Wilhelmshaven.
She's waited until everything was ready."
"That what they mean by the red light markers, then?"
"Yes. They could be on the roofs of houses, and masked, so that they
wouldn't be seen except from overhead. They'd be in certain fixed
positions, and the men on the Zeppelins would be able to calculate their
aim, and drop their bombs so many degrees to the left or right of the
red marking lights."
"But we've got aeroplanes flying about, haven't we?" said Jack.
"Wouldn't they see those lights and wonder about them?"
"Yes, if they were showing all the time. But you can depend on it that
these Germans have provided for all that. They will have arranged for
the Zeppelin to be above the position, as near as they can guess them,
at certain times--and the lights will only be shown at those times, and
then only for a few seconds. Even if someone else sees them, you see,
there won't be time to do anything."
"You must be right, Harry!" said Jack, nervously. "There's no other way
to explain that message. How are we going to stop them?"
"I don't know yet, but we'll have to work out some way of doing it. It
would be terrible for us to know what had been planned and still not be
able to stop them! I wish I knew were Graves was. I'd like to ..."
He stopped, thinking hard.
"What good would that do?"
"Oh, I don't want him--not just now. But I don't want him to see me just
at present. I want to know where he is so that I can avoid him."
"Suppose I scout into Bray?" suggested Jack. "I can find out something
that might be useful, perhaps. If any of them from Bray Park have come
into the village today I'll hear about it."
"That's a good idea. Suppose you do that, Jack. I don't know just what
I'll do yet. But if I go away from here before you come back, Dick will
stay. I've got to think--there must be some way to beat them!"