"But you understand the naval code, too, don't you?"
The manner in which the question was worded put Ned on his guard. He saw that it would be better to reply in the negative.
"No," he said, shaking his head, "I haven't had much to do with the signal part of man-o'-war work; but, of course, I learned something of wireless at the naval school."
"Good!" exclaimed Herr Muller; "come with me."
He ushered the boys below—for Herc had trailed along—and into the small wireless room Ned had noticed.
"I am expecting a message at any time now," he said; "but it will come in cipher. Get it absolutely accurate and you will not suffer by it."
Ned nodded.
"Better see about hoisting your aerials," he said.
Herr Muller hurried off on this errand, while Ned looked over the instruments surrounding him. They glistened with brass and polished steel in the smoky light of a bulkhead lamp. But despite the evident haste with which they had been installed, it was easy to see that the apparatus was the finest obtainable.
"What on earth can be up now?" wondered Herc, as Ned took up the metal headpiece and adjusted it.