"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, although far up on the crest of Lenox Hill the receding lights of one were just vanishing.

"Do you see any policemen?" she asked in a low voice.

"Not one. They're all frozen to death, I suppose, as we will be in a few minutes."

They turned into Madison Avenue past the Hotel Ess.e.x. There was not a soul to be seen. Even the silver-laced porter had retired from the freezing vestibule. A few moments later Miss Erith paused before a shop on the ground floor of an old-fashioned brownstone residence which had been altered for business.

Over the shop-window was a sign: "H. Lauffer, Frames and Gilding."

The curtains of the shop-windows were lowered. No light burned inside.

Over Lauffer's shop was the empty show-window of another shop--on the second floor--the sort of place that milliners and tea-shop keepers delight in--but inside the blank show-window was pasted the sign "To Let."

Above this shop were three floors, evidently apartments. The windows were not lighted.

"Lauffer lives on the fourth floor," said Miss Erith. "Will you please give me the jimmy, Vaux?"

He fished it out of his overcoat pocket and looked uneasily up and down the deserted avenue while the girl stepped calmly into the open entryway. There were two doors, a gla.s.s one opening on the stairs leading to the upper floors, and the shop door on the left.

She stooped over for a rapid survey, then with incredible swiftness jimmied the shop door.

The noise of the illegal operations awoke the icy and silent avenue with a loud, splitting crash! The door swung gently inward.

"Quick!" she said. And he followed her guiltily inside.

The shop was quite warm. A stove in the rear room still emitted heat and a dull red light. On the stove was a pot of glue, or some other substance used by gilders and frame makers. Steam curled languidly from it; also a smell not quite as languid.

Vaux handed her an electric torch, then flashed his own. The next moment she found a push b.u.t.ton and switched on the lights in the shop. Then they extinguished their torches.

Stacks of frames in raw wood, frames in "compo," samples gilded and in natural finish littered the untidy place. A few process "mezzotints" hung on the walls. There was a counter on which lay twine, shears and wrapping paper, and a copy of the most recent telephone directory. It was the only book in sight, and Miss Erith opened it and spread her copy of the cipher-letter beside it. Then she began to turn the pages according to the numbers written in her copy of the cipher letter.

Meanwhile, Vaux was prowling. There were no books in the rear room; of this he was presently a.s.sured. He came back into the front shop and began to rummage. A few trade catalogues rewarded him and he solemnly laid them on the counter.

"The telephone directory is NOT the key," said Miss Erith, pushing it aside. A few moments were sufficient to convince them that the key did not lie within any of the trade catalogues either.

"Have you searched very carefully?" she asked.

"There's not another book in the bally shop."

"Well, then, Lauffer must have it in his apartment upstairs."

"Which apartment is it?"

"The fourth floor. His name is under a bell on a bra.s.s plate in the entry. I noticed it when I came in." She turned off the electric light; they went to the door, reconnoitred cautiously, saw n.o.body on the avenue. However, a tramcar was pa.s.sing, and they waited; then Vaux flashed his torch on the bell-plate.

Under the bell marked "Fourth Floor" was engraved Herman Lauffer's name.

"You know," remonstrated Vaux, "we have no warrant for this sort of thing, and it means serious trouble if we're caught."

"I know it. But what other way is there?" she inquired naively. "You allowed me only twenty-four hours, and I WON'T back out!"

"What procedure do you propose now?" he asked, grimly amused, and beginning to feel rather reckless himself, and enjoying the feeling.

"What do you wish to do?" he repeated. "I'm game."

"I have an automatic pistol," she remarked seriously, tapping her fur-coat pocket, "--and a pair of handcuffs--the sort that open and lock when you strike a man on the wrist with them. You know the kind?"

"Surely. You mean to commit a.s.sault and robbery in the first degree upon the body of the aforesaid Herman?"

"I-is that it?" she faltered.

"It is."

She hesitated:

"That is rather dreadful, isn't it?"

"Somewhat. It involves almost anything short of life imprisonment.

But _I_ don't mind."