The Shadow's light was on the floor and along the wall. The hand, now gloved, tapped the panel. It sought everywhere for some secret contrivance. It found nothing but smooth surface.
The light went out. The Shadow was pondering, in the midst of Stygian gloom. His intuitive mind had declared that there must be some entrance here.
Wellington had hinted that fact, Salisbury had said, but the police ridiculed the idea.
Searchers had examined the room. They had not even suspected anything amiss.
The Shadow knew that something lay on the other side of that wall. He was considering one fact. Was it possible that the only way of forcing this barrier lay from the other side?
A plausible possibility. With no means of operating from this room, no one could discover the opening. But that also meant a disadvantage. It meant that should any one enter here and close the way behind him, he would have no means of exit.
A low, eerie laugh sounded in the darkness. The Shadow's light showed on the smooth panel; then turned and shone upon the upright pickets of the metal barrier. These were divided by a horizontal bar at the center.
The black hand gripped each lower post in turn, starting with the wall and moving away.
After a short space, it started backward along the upper tier.
These upright bars were square in shape. One, set at a slight angle, twisted a trifle under the powerful grasp. Hidden eyes observed that the lower portion of the post — below the horizontal rail — did not respond to the twist. The bar was in two sections!