"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