"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."