Presently Carter rose and stretching himself lazily, as if about to leave, turned to face the Drive, his keen eyes taking in all the passers-by.  Apparently satisfied, he sat down abruptly and turned to speak to the girl beside him.

“All right, K-19,” he said, “it’s safe.  Now we can talk.”

“I’ve got such a lot to tell,” cried Jane.

“First,” said Carter, “just where did you put that cipher message when you put it back?”

“What!” cried the girl, her face blanching, “wasn’t it there?  Didn’t you find it?”

Carter shook his head.

“It must be there,” she insisted.  “Are you sure you looked in the right book—­the fifth book from the end on the second shelf on the up-town side of the store.”

“It’s not there.  I examined every book there, on the shelves above and below and at the other end, too.”

“The clerk in the store, that girl—­must have hidden it,” cried Jane with conviction.

“That’s not likely.  She’s an English girl—­from Liverpool.  She has three brothers fighting on the Allies’ side.  We can leave her out of it.”

“Who else could have taken it?”

“There’s only one answer,” said Carter slowly and impressively.  “Some one went into that store between the time you copied the message and the time I met you at the drug-store.  You told me no one but a couple of girls had entered.  Was there any one else?  Think—­think!”

“There was no one,” said Jane thoughtfully, “no one except the two girls together.  I never thought of suspecting them.”

“What did they look like?  Could you identify them?”

“I did not notice them particularly,” Jane confessed.  “I was expecting Mr. Hoff’s confederate to be a man.”

“They’re using a lot of women spies,” asserted Carter.  “Don’t you remember what the girls looked like?”

“One of them,” said Jane thoughtfully, “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.”