checks.

So Harry had another glimpse of the effects of war, seeing how it
affected a great many people who not only had nothing to do with
the fighting, but were citizens of a neutral nation. He was
beginning to understand very thoroughly by this time that war was
not what he had always dreamed. It meant more than fighting, more
than glory.

But, after all, now that war had come, it was no time to think of
such things. He had undertaken, if he could get permission, to do
a certain very important piece of work. And now, by a happy
accident, as he regarded it, it wasn't necessary for him to ask
that permission. He was not forbidden to do any particular thing;
his father had simply warned him to be careful.

So when he went home, he whistled outside of Dick Mercer's window,
woke him up, and, when Dick came down into the garden, explained
to him what Colonel Throckmorton wanted them to do.

"He said I could pick out someone to go with me, Dick," Harry
explained. "And, of course, I'd rather have you than anyone I can
think of. Will you come along?"

"Will I!" said Dick. "What do you think you'll do, Harry?"

"We may get special orders, of course," said Harry. "But I think
the first thing will be to find out just where the signals from
that house are being received. They must be answered, you know,
so we ought to find the next station. Then, from that, we can