ht here in New York, more than
likely by the very people next door.

With her pretty lips set in a resolute line she left the house and
walked rapidly north. Come what may she would go on with it. Her country
needed her, and that was all-sufficient.

CHAPTER VI

THE MISSING MESSAGE

After Jane left Carter at the drug-store, he did not cross immediately
to the bookshop opposite. His detective work was not of that sort. He
strolled leisurely around the corner long enough to give some directions
to his two aides waiting there and then, moving across the street,
paused in front of the window of books as if something there had
attracted his attention. All the while he was keeping a sharp eye for
any person who looked as if they might be connected in any way with old
Hoff. Satisfied that his entrance was unobserved he strolled casually in
and began looking over the volumes in the lending library. The lone
clerk in the store--a young woman--at first volunteered some
suggestions, but as they went unheeded she returned to her work of
posting up the accounts.

As soon as her attention was occupied Carter moved at once to the end
of the shelf that Miss Strong had indicated and removed the fifth book.
To his amazement he found nothing whatever concealed between the leaves.
The books on either side on the same shelf failed to yield up anything.
He tried the shelf above and the shelf below. Perhaps Miss Strong had
been mistaken in the directions. He examined the books at the other end.
There was nothing there. He recalled that the girl had said that no one
except two girls had entered the store between the time she had
discovered and copied the cipher and the time of his arrival. If these
girls had not taken the message away there could be only one other
explanation--the clerk in the bookstore must have removed it and
concealed it somewhere.

"Which of the war books do you think the best?" he asked for the purpose
of starting a conversation.

"There's that many it is hard to say, sir," the young woman answered.

Something in her inflection made him look sharply at her. Her accent
surely was English, or possibly Canadian. A few judicious questions
quickly brought out the information that she came from Liverpool and
that she had three brothers in the British army. Carter decided that it
was preposterous to suspect her of being in league with German agents.
There was only one other thing that could have happened. Some one