The wall had been divided into three panels, with a high wainscoting.

Inch by inch he examined it from one end to the other; he started from the back and came toward the front.

About three-quarters of the way there, he paused.

It was very simple, after all.

The solid wall for a couple of feet suddenly ceased, and the design was continued with an expanse of stretched canvas, which yielded easily to his finger.