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 glass 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 button 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 assured. 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 brass 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 nobody on the avenue. However, a tramcar was passing, 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."