g and laid down his pencil. His chief picked
up the sheet of paper and scanned the long line of letters Henry had
made, like this:

EEANNRDBOEUNRYWSEUTTERONSNNFEEIAYWMNVTTASANXJULEIGOKWSNVATYIZLETK

"Sixty-five," he said aloud, after counting the letters carefully.

A frown came over his face as he stood looking at the paper in his
hand. "Sixty-five," he repeated. "All their other cipher messages
have made four even lines. You can't divide sixty-five evenly by four.
Boys, I believe--but we'll make sure first."

He sank into a chair, laid the paper on the desk, and arranged the
letters according to the old plan, thus:

EEANNRDBOEUNRYW
SEUTTERONSNNFEE
IAYWMNVTTASANXJ
ULEIGOKWSNVATYI

"I don't know what to do with the five letters left over," he said, as
he laid down his pencil. Then as he ran his eye down column after
column and across each line, he continued, "But I guess it makes no
difference. It is just as I thought. I feel more certain than ever
that something of great importance is afoot. They've switched to
another cipher."

CHAPTER XVII

A CHANGE IN CIPHERS

For some moments there was a complete silence in the room. The members
of the wireless patrol looked at one another in astonishment,
questioning with their eyes the meaning of this new turn of events.
Captain Hardy sat staring at the message before him, his brow wrinkled,
his eyelids drawn close together, trying to find some new clue to the
puzzle before him. And until he spoke, the lads of the little patrol
forbore to utter a sound. So for some time the room remained as silent
as a tunnel.

At last the captain glanced up from his paper and noted the intent
looks bent upon him, and the deep silence. He shook off his
abstraction.

"It looks as though we were up against it," he said. "Every minute I
feel more certain that something serious has happened. Why should they
be sending radio messages at this hour, when they have never sent them
before excepting after the transports sailed? And why should they now
use a new cipher? Their plan evidently was to use radio communication
as little as possible, lest they be detected. So they sent nothing by
wireless but the most important news--the news of ship movements, which
had to be got to Germany at once. All other messages they conveyed in
some slower but safer way. We know they used the telephone, and sent
messages by a boy, and wrote on dollars, and carried mes