letter or envelope, either, except what we saw."
The girl nodded. On a large table behind her chair lay a portfolio. She turned, drew it toward her, and lifted it into her lap.
"What have you discovered?" he inquired politely, basking in the grateful warmth of the fire.
"Nothing. The cipher is, as I feared, purely arbitrary. It's exasperating, isn't it?"
He nodded, toasting his shins.
"You see," she continued, opening the portfolio, "here is my copy of this wretched cipher letter. I have transferred it to one sheet. It's nothing but a string of Arabic numbers interspersed with meaningless words. These numbers most probably represent, in the order in which they are written, first the number of the page of some book, then the line on which the word is to be found—say, the tenth line from the top, or maybe from the bottom—and then the position of the word—second from the left or perhaps from the right."
"It's utterly impossible to solve that unless you have the book," he remarked; "therefore, why speculate, Miss Erith?"
"I'm going to try to find the book."
"How?"
"By breaking into the shop of Herman Lauffer."
"House-breaking? Robbery?"
"Yes."
Vaux smiled incredulously:
"Granted that you get into Lauffer's shop without being arrested, what then?"
"I shall have this cipher with me. There are not likely to be many books in the shop of a gilder and maker of picture frames. I shall, by referring to this letter, search what books I find there for a single coherent sentence. When I discover such a sentence I shall know that I have the right book."
The young man smoked reflectively and gazed into the burning coals.
"So you propose to break into his shop to-night and steal the book?"
"There seems to be nothing else to do, Mr. Vaux."
"Of course," he remarked sarcastically, "we could turn this matter over to the proper authorities—"
"I WON'T! PLEASE don't!"
"Why not?"
"Because I have concluded that it IS part of our work. And I've begun already. I went to see Lauffer. I took a photograph to be framed."
"What does he look like?"
"A mink—an otter—one of those sharp-muzzled little animals!—Two tiny eyes, rather close together, a long nose that wrinkles when he talks, as though he were sniffing at you; a ragged, black moustache, like the furry muzzle-bristles of some wild thing—that is a sketch of Herman Lauffer."
"A pretty man," commented Vaux, much amused.
"He's little and fat of abdomen, but he looks powerful."
"Prettier and prettier!"
They both laughed. A pleasant steam arose from the tall glass at his elbow.
"Well," she said, "I have to change my gown—"
"Good Lord! Are we going now?" he remonstrated.
"Yes. I don't believe there will be a soul on the streets."
"But I don't wish to go at all," he explained. "I'm very happy here, discussing things."
"I know it. But you wouldn't let me go all alone, would you, Mr. Vaux?"
"I don't want you to go anywhere."
"But I'm GOING!"
"Here's where I perish," groaned Vaux, rising as the girl passed him with her pretty, humorous smile, moving lithely, swiftly as some graceful wild thing passing confidently through its own domain.
Vaux gazed meditatively upon the coals, glass in one hand, cigarette in the other. Patriotism is a tough career.
"This is worse than inhuman," he thought. "If I go out on such an errand to-night I sure am doing my bitter bit. … Probably some policeman will shoot me—unless I freeze to death. This is a vastly unpleasant affair…. Vastly!"
He was still caressing the fire with his regard when Miss Erith came back.
She wore a fur coat buttoned to the throat, a fur toque, fur gloves. As he rose she naively displayed a jimmy and two flashlights.
"I see," he said, "very nice, very handy! But we don't need these to convict us."
She laughed and handed him the instruments; and he pocketed them and followed her downstairs.
Her car was waiting, engine running; she spoke to the Kadiak chauffeur, got in, and Vaux followed.
"You know," he said, pulling the mink robe over her and himself, "you're behaving very badly to your superior officer."
"I'm so excited, so interested! I hope I'm not lacking in deference to my honoured Chief of Division. Am I, Mr. Vaux?"
"You certainly hustle me around some! This is a crazy thing we're doing."
"Oh, I'm sorry!"
"You're an autocrat. You're a lady-Nero! Tell me, Miss Erith, were you ever afraid of anything on earth?"
"Yes."
"What?"
"Lightning and caterpillars."
"Those are probably the only really dangerous things I never feared," he said. "You seem to be young and human and feminine. Are you?"
"Oh, very."
"Then why aren't you afraid of being shot for a burglar, and why do you go so gaily about grand larceny?"
The girl's light laughter was friendly and fearless.
"Do you live alone?" he inquired after a moment's silence.
"Yes. My parents are not living."
"You are rather an unusual girl, Miss Erith."
"Why?"
"Well, girls of your sort are seldom as much in earnest about their war work as you seem to be," he remarked with gentle irony.
"How about the nurses and drivers in France?"
"Oh, of course. I mean nice girls, like yourself, who do near-war work here in New York—"
"You ARE brutal!" she exclaimed. "I am mad to go to France! It is a sacrifice—a renunciation for me to remain in New York. I understand nursing and I know how to drive a car; but I have stayed here because my knowledge of ciphers seemed to fit me for this work."
"I was teasing you," he said gently.
"I know it. But there is SO much truth in what you say about near-war work. I hate that sort of woman…. Why do you laugh?"
"Because you're just a child. But you are full of ability and possibility, Miss Erith."
"I wish my ability might land me in France!"
"Surely, surely," he murmured.
"Do you think it will, Mr. Vaux?"
"Maybe it will," he said, not believing it. He added: "I think, however, your undoubted ability is going to land us both in jail."
At which pessimistic prognosis they both began to laugh. She was very lovely when she laughed.
"I hope they'll give us the same cell," she said. "Don't you?"
"Surely," he replied gaily.
Once he remembered the photograph of Arethusa in his desk at headquarters, and thought that perhaps he might need it before the evening was over.
"Surely, surely," he muttered to himself, "hum—hum!"
Her coupe stopped in Fifty-sixth Street near Madison Avenue.
"The car will wait here," remarked the girl, as Vaux helped her to descend. "Lauffer's shop is just around the corner." She took his arm to steady herself on the icy sidewalk. He liked it.
In the bitter darkness there was not a soul to be seen on the street; no tramcars were approaching on Madison Avenue,