to read now. At once I recalled Burke's
shadow on the blind; he had been bending over this table, and the agile
movements of his hands were no longer mysterious. He, too, had some
knowledge of the cipher, and he had been rapidly running over the
tack-heads, hunting for the combination that would reveal a concealed
compartment.

After a while we grew rational again. I got out the cipher, and once
more Genevieve and I put our heads together over it. Here it is; you
may follow us while we dig it out:

[Illustration: Cipher]

"If you remember," I said presently, "I told you that very likely it
would have to be interpreted in connection with something not on the
paper. Count the tacks along the front edge."

There were nineteen of them.

"Counting from either end," I went on, "the centre tack will be ten.
It 's as simple as A-B-C. That's our starting-point from which to find
the others. Find the fourth one to the right of the centre
tack--number ten."

She placed the tip of one forefinger upon it--a bit gingerly, I smiled
to see.

"Why, it gives!" she announced in surprise.

"I 'd be terribly cut up if it did n't," said I. "Now, then, the
eleventh to the right."

This carried her to the third one around the side; number thirteen was
the fifth on the left side, number seventeen the ninth on the right
side, while number five was on the front edge, of course, close to the
centre. Each of them yielded a trifle beneath her pressure--until she
came to number five. Here she drew back and clasped her hands tightly
together.

"Oh, I can't!" she cried excitedly. "I'm just so nervous that I can't
put my finger upon it. You do it."

"Nonsense!" said I. "If you don't find the ruby, it will never be
found. That's the last one."

At last, with shining eyes and parted lips, the little finger went
slowly down upon the fateful tack-head. She screwed up her eyes and
closed her lips tightly, as if she feared something would explode, then
pushed with all her might. The tack gave; but nothing else happened.

We stared at the table, our faces long with disappointment; then we
looked at each other in unspoken questioning. Genevieve's expression
was so woe-begone that I laughed. The nerve-racking suspense was
broken.

"How silly!" she exclaimed. "There!"

With a quick movement, she bore down upon the centre tack--number
ten--and lo! a section of the table edge flew outward, disclosing an
aperture perhaps six