On the table was a typewriter, in the pigeon-holes were folded papers, neatly ticketed and enclosed in rubber bands. Aside from the underground smell the place was tolerably comfortable. The air was damp and chilly, but Ned was well clothed and did not mind that.

As has been said, the boy was now in no haste to leave the place. He believed that the mystery he had been sent out to solve would be solved there. For an hour or more he searched over the place, opening the folded papers and making a close examination of the typewriter and the stock of unused paper in the drawer of the table.

At length, his examination completed, he passed back into the chamber behind the rug and listened at the opening through which he had entered. A sound of the steady beat of blows reached his ears at first, then a low whistle. That was Jimmie, he knew. The lad had a habit of whistling softly to himself, usually without time or tune.

Waiting for a lull in the blows, he rapped softly on the box which backed up against the opening. Instantly the whistling ceased, and Jimmie’s voice was heard.

“Come on out,” the boy said. “I’ve been kicking my heels against this box for an hour, waitin’ for you to signal back.”

“Be sure there is no one watching,” Ned cautioned.

He heard Jimmie walking away, then heard him coming back. In a moment the box was drawn away from the opening.

“You’ve been in there long enough to dig through to China,” Jimmie said, as Ned stood by his side. “What did you find in there?”

“A double keyboard typewriter,” grinned Ned.

“Quit your kiddin’,” answered Jimmie. “You’ll be claimin’ next that you found a brass band in there.”