Presently he brought up in front of one of the larger pillars supporting the balcony. He had previously noticed its huge dimensions, and now he gauged them again with a quickly calculating eye. It was there The Gray Phantom had stood when the mysterious shot was fired the other day, and Helen Hardwick had been leaning against the same pillar when the curious individual with the repulsive features glided past her.
The electric gleam moved swiftly over the white surface of the post with its ornate trimmings of dull gold. Again, as once or twice before, he wondered whether there was any hidden significance in the fact that The Gray Phantom had stood in this identical spot at the moment the shot was fired. Was it possible that the skulking assailant had feared that The Phantom was about to make an important discovery, and was that why he had fired the shot? Culligore pondered the question while scanning every square inch of the pillar.
Suddenly the electric gleam stopped at a point near the floor, and Culligore could scarcely repress an exclamation of elation. His ruse had succeeded, for on the white surface of the post was a faint discoloration which signified that Starr's hand had recently touched that particular point. There were no other marks, and this one was only a few inches from the floor. Culligore's fingers ran quickly over the surrounding space, and occasionally he pressed his thumb firmly against the wood, but without discovering anything. His hand slid downward to where the rich Persian carpet was neatly tucked around the base of the post, and suddenly his exploring fingers touched a slight knoblike projection. He pressed firmly, and he felt an exultant tingle as there came a soft, whirring response. A panel in the post, ingeniously hidden in the gold-lined grooves, was sliding back, forming an aperture.
The electric gleam showed a look of keen elation on Culligore's face. His discovery had taken only a minute or two of valuable time, for he had moved fast since he noticed that Starr was gone. Yet, but for a happy inspiration and the resultant reddish stain on the post, he might have searched for days without finding the opening.
Now he squeezed his figure through the narrow aperture, at the same time pocketing his electric flash and drawing his automatic. His feet encountered the upper rungs of a ladder that pointed straight down. He descended rapidly, making no sound. At the bottom was a narrow passage extending in the direction of the street, and at its farther end he saw a faint glow. He approached quickly, warned by a sixth sense that he had no time to waste.