"A copy of that book is, presumably, in possession of the man to whom this letter is addressed." "Surely--surely. Hum--hum! What's his name, Miss Erith?"--glancing down at the yellow envelope. "Oh, yes--Herman Lauffer--hum!" He opened a big book containing the names of enemy aliens and perused it, frowinng. The name of Herman Lauffer was not listed. He consulted other volumes containing supplementary lists of suspects and undesirables--lists furnished daily by certain services unnecessary to mention. "Here he is!" exclaimed Vaux; "--Herman Lauffer, picture-framer and gilder! That's his number on Madison Avenue!"--pointing to the type-written paragraph. "You see he's probably already under surveillance-one of the several services is doubtless keeping tabs on him. I think I'd better call up the--" "Please!--Mr. Vaux!" she pleaded. He had already touched the telephone receiver to unhook it. Miss Erith looked at him appealingly; her eyes were very, very hazel. "Couldn't we handle it?" she asked. "WE?" "You and I!" "But that's not our affair, Miss Erith--" "Make it so! Oh, please do. Won't you?" Vaux's arm fell to the desk top. He sat thinking for a few minutes. Then he picked up a pencil in an absent-minded manner and began to trace little circles, squares, and crosses on his pad, stringing them along line after line as though at hazard and apparently thinking of anything except what he was doing. The paper on which he seemed to be so idly employed lay on his desk directly under Miss Erith's eyes; and after a while the girl began to laugh softly to herself. "Thank you, Mr. Vaux," she said. "This is the opportunity I have longed for." Vaux looked up at her as though he did not understand. But the girl laid one finger on the lines of circles, squares, dashes and crosses, and, still laughing, read them off, translating what he had written: "You are a very clever girl. I've decided to turn this case over to you. After all, your business is to decipher cipher, and you can't do it without the book." They both laughed. "I don't see how you ever solved that," he said, delighted to tease her. "How insulting!--when you know it is one of the oldest and most familiar of codes--the 1-2-3 and _a-b-c_ combination!" "Rather rude of you to read it over my shoulder, Miss Erith. It isn't done--" "You meant to see if I could! You know you did!" "Did I?" "Of course! That old 'Seal of Solomon' cipher is perfectly transparent." "Really? But how about THIS!"--touching the sheets of the Lauffer letter--"how are you going to read this sequence of Arabic numerals?" "I haven't the slightest idea," said the girl, candidly. "But you request the job of trying to find the key?" he suggested ironically. "There is no key. You know it." "I mean the code book." "I would like to try to find it." "How are you going to go about it?" "I don't know yet."