“What does that young Hoff do who was here last night?” her father had asked at the breakfast table.

“He’s in the importing business with his uncle, I think,” she had answered.

“Where’d you meet him?”

“He lives in the apartment next door.  Lieutenant Kramer introduced him.”

“He’s German, isn’t he?”

“Oh, no,” said Jane, almost unconsciously rallying to defend him, “he was born in this country.”

“Well, it’s a German name.”

“Don’t you like him?”

“He talks well,” her father said, “and seems to be well-bred.”

It was with reluctance, too, that Jane admitted to herself that the better acquainted she became with Frederic Hoff the more fascinating she found his society.  She was always expecting that by some word or action he would reveal to her his true character.  At the matinee she had waited anxiously to see what he would do when the orchestra played the national anthem.  To her amazement he was on his feet almost among the first and remained standing in an attitude of the utmost respect until the last bar was completed.  If he were only pretending the role of a good American, he certainly was a wonderful actor.  As her admiration for him increased and her interest in him grew she found that almost her only antidote was to try to keep thinking of his face as she had seen it the night that K-19—­the other K-19—­had been so mysteriously murdered.  She kept wondering if Chief Fleck had made any further discoveries about the murder and resolved to ask him about it at the first opportunity.  She therefore was delighted when on Tuesday, as she made her regular report by telephone, he asked if she could come to his office that afternoon with Dean to discuss some matters of importance.  They found Carter already with the chief when they arrived.

“Thanks to your work, Miss Strong, and to Dean’s dictograph,” said the chief, “we have made considerable progress.  We have learned a lot more about the cipher messages.”

“You have learned it through me,” cried Jane in amazement.

“Yes,” said the chief, smiling, “from that list of names you reported.”

“What were they, a cipher, a code?” questioned the girl breathlessly.

“No, nothing like that.  They are merely the names of various innocent and unsuspecting booksellers in various parts of the city.”

“How did you discover that?”

“In the simplest and easiest way possible.  I listed all the names you reported and studied them carefully, trying to find their common denominator.  They were not in the same neighborhood, so it was not locality.  They were not all German, so it was not racial.  I looked them up in the telephone directory, checking up the numbers of the telephones of the Jones, the Simpsons, but that gave no clue.  Then, as I looked through the telephone lists, I discovered that there was a bookstore kept by a man of each name.  Then I understood.  It is a simple plan for throwing off shadowers.”