He walked to the end of the block, then crossed the street and moved up the side on which the Bimble house stood. There were a few pedestrians in the street, and to attempt to force the main door might prove unsafe. The basement entrance was dark, and in a moment, concealed by the shadows, he was at work on the lock. It yielded so easily to his deft manipulation that he could understand how the prowlers of whom Bimble had complained had managed to enter the house.
Pulling the door shut, he took out his electric flash, determined to settle his suspicions by making a systematic search of the house. He proceeded swiftly but with care, searching every nook and cranny and occasionally tapping the walls and floors to make sure there were no hollow spaces. He explored cellar and basement without finding anything of suggestive nature, then walked up the same stairway he had ascended after his first trip through the tunnel.
He was now in the laboratory, sweeping floor and walls with the electric torch. At first glance it looked exactly as it had when Helen met him at the head of the stairs with a leveled pistol, yet he sensed a difference almost at once. His eyes flitted over the long workbench with its collection of chemical apparatus, over the black-framed photographs and X-ray prints, and then he glanced at the tall cages along the wall, in which the skeletons stood, erect and grim as ghostly sentinels.
It was then his mind grasped the difference. On his first visit there had been at least a dozen skeletons in the room; now he counted only seven. The famous Raschenell, to whom Bimble had pointed with so much pride, was among the missing ones. He paused only for a moment to wonder what had become of the others, for Bimble and the servant might return at any time and interrupt his search, and he wished to be at the Turkish coffee house not later than half past ten.
He inspected room after room, but without result, finally mounting to the attic and making the same thorough investigation there. He had found nothing whatever to reward him for his efforts. He came to the conclusion that his suspicions had been entirely unfounded, for if they had had any basis in fact his investigation would have uncovered some clew or hint pointing in that direction. One thing had been accomplished, however, was his reflection as he walked down the stairs. He had eliminated Doctor Bimble from the range of his suspicions and would waste no more time and effort trying to explain the eccentricities of a scientist.
Deciding to leave the way he had entered, he crossed the laboratory and moved toward the stairs. With his hand on the doorknob, he looked back and once more let his electric torch play over the floor and walls. Again, without exactly knowing why, he counted the cages, vaguely feeling that there was a hidden significance in the depletion of the grisly company.
Finally, he extinguished his flash and resolutely turned away. Again he was berating himself for bothering his mind over trivial things. Doubtless Doctor Bimble had a sound and simple reason for removing a number of the skeletons. As he walked down the basement stairs he resolved to banish the anthropologist and his collection from his thoughts.
An odd sense of apprehension took hold of him as he reached the bottom step. He looked about him sharply; the darkness was so thick that he could see nothing. He pricked up his ears and listened, but he could detect no sound except those coming from the street. Yet he had a feeling that he was not alone, that another being was lurking somewhere in the darkness. It was a familiar sensation and he had learned to heed its warning, for he had experienced it before in moments of danger.
He stepped down on the floor, at the same instant reaching for the pistol he had taken from Dan the Dope. Before he could draw the weapon a voice spoke sharply:
“Stay right where you are, friend!”