ully, "wore an odd-shaped hat, a sort
of a tam with a red feather."

"Would you know the hat again if you saw it?"

"I think--I'm sure I would."

"Well, that's something. Watch for that hat, and if you ever see it
again trail the girl till you find out where she lives. If you locate
her telephone Mr. Fleck at once. And now, what has happened to you?"

"I've so much to tell, important, very important, I think."

She hesitated, wondering how much Carter was in the chief's confidence.
Did he know the import of the cipher message she had discovered? Ought
she to talk freely to him?

"Do you know what those numbers meant?" she asked.

"Yes," he replied, "about the eight transports sailing. The Chief told
me about it."

"Well," she said, with a sigh of relief, "I have become acquainted with
young Mr. Hoff already. I've just had luncheon with him."

"That's fine," he cried enthusiastically. "A lucky day it was I ran
across you."

"When you 'phoned me he was there in our apartment, he and a navy
lieutenant, Mr. Kramer."

Attentively he listened as she told of the ruse by which she had
inveigled them into coming to luncheon, reminding him that it was the
same naval officer that he himself had seen in close conversation with
Hoff at the Ritz the day before. He nodded his head in a satisfied way.

"They are together too much to be up to any good," he commented. "Tell
me the rest. What made you so rattled when I 'phoned you?"

He listened intently as she told of finding young Hoff standing right
behind her as she had inadvertently mentioned aloud "the fifth book."

"Do you suppose," she questioned anxiously, "that he overheard me and
understood what we were talking about? He left right away after that. I
do hope I didn't betray the fact that they are being watched."

"We can't tell yet," said Carter. "The precautions they take and the
roundabout methods they have of communicating with each other show that
all Germany's spies constantly act as if they knew they were under
surveillance. In fact, I suppose every German in this country, whether
he is a spy or not, can't help but notice that his neighbors are
watching him--and well they might."

"I don't see why," cried Jane, "Mr. Fleck did not have old Mr. Hoff
locked up right away. He could not do any more damage then, or be
sending any more messages about our transports."

"That wouldn't have done the least bit of good," said Carter decisively.
"Watching our tran