It seemed a long time before the work in the chamber ceased, and Ned had plenty of time in which to review the strange case he was interested in. The transition from gay New York to that weird apartment seemed almost like a whiff of fancy. Then he recalled the painstaking surveillance of the fellow called “His Nobbs” on the way down, and smiled at the thought that the plans he had made at first sight of the spy had worked out remarkably well.
He had submitted gracefully to the surveillance, knowing that in time the man who was following him would track him to his camp on the Isthmus. That was the very point. He would not know where to look for the plotters, but they would know where to look for him. He depended on them to send a man to work him mischief, and reckoned on being able to follow that man back to his principals.
This they had done. The men who had employed the spy on the ship had acted quickly and had sent a bomb-thrower. Ned shuddered as he thought of the risk he had taken that night in going to bed without leaving a guard. He had overlooked a point in the game there, for he had not apprehended such prompt action on the part of the men he had pitted himself against.
However, the plan had miscarried because of his waking at the critical moment, and here he was, at the door of the men who had sent the man about their murderous work. But were these the principals? When he thought of the two who had hastened off toward Gatun in a motor car he did not believe that they were.
“I shall have to look in other places besides subterranean chambers for the men in charge,” he thought. “These fellows are merely tools.”
Presently the sharp click-click of metal came no more through the heavy air of the room, and Ned, awaking Jimmie, who had fallen asleep again, moved into the small room from which the doorway gave a view of the stairs. He could see from this room that the sun was shining brightly outside.
Ned had scarcely stationed himself in the heavy shadows back of the doorway when four men came down the passage and passed him. He had no doubt that they were the workmen going out for the day. Such work as they did must needs be done in the night.
Two of the men were tall and slim, with Spanish-looking faces, and two were short and stout, with a heavy droop to their shoulders and broad faces almost entirely covered with whiskers.
“The original anarchists,” whispered Jimmie, as the two short men passed.
After the disappearance of the workmen all was still in the underground rooms. The door to the work-chamber had been left open, and Ned knew that one of two things was the solution to this.