Part 18 (2/2)

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 d.i.c.k's escape, and of his meeting with Jack. He nodded at the story they had heard from Gaffer 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 got in 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 they got d.i.c.k. But I got away, and I managed to stay fairly close to them. I followed them when they left d.i.c.k 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 d.i.c.k out? And did you hear them saying anything that sounded as if it might be useful, d.i.c.k?”

”That was fine work!” he said, when he had heard a description of d.i.c.k's rescue. ”Jack, you seem to be around every time one of us gets into trouble and needs help!”

Then d.i.c.k 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 d.i.c.k mentioned. Then he took a paper from his pocket.

”Remember this, d.i.c.k?” 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 that 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're probably stuck, but I think it's 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 princ.i.p.al 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 d.i.c.k 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 of 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 d.i.c.k, 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 d.i.c.k. ”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, d.i.c.k understood.

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