"Am I to go, too?"
"Certainly. You gave me only twenty-four hours, and I can't do it alone in that time."
He said nothing, but his thoughts concentrated upon a single unprintable word.
"What have you done with the original Lauffer letter, Mr. Vaux?" she inquired rather nervously.
"The usual. No invisible ink had been used; nothing microscopic. There was nothing on the 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."