"He could not hear a thing from this world if he is hiding in the other," he said. "Sound is similar to light in that respect. There are sounds too high or too low in pitch to be heard by our limited auditory capacities. The desperado would have to be right here and visible to hear what we say. He may watch every move I make now, for he warned me that I would be a dead man, the first attempt I made to follow him into the Fifth Dimension."
Steckel's eyes continued to flash apprehensively. "Why, the devil might have designs on my life," he said. "He might pop up at any moment, kill me for the good of the underworld, and vanish again! Or he might kill you if he thought you could duplicate the apparatus!"
Mortenson scrutinized the chief thoughtfully.
"He doesn't, chief," he said seriously. "At least that is my impression. I told him I had no plans of the instrument; that I could not duplicate them. Had he believed otherwise, I'd have gotten his bullet instead of a crack on the skull."
"But you can duplicate them, Mortenson?" the chief asked eagerly.
Mortenson laughed shrewdly. "Of course," he replied. "I have a complete set of plans. I merely lied to save my neck!"
"You intend to use them, then?" Steckel inquired, leaning forward.
The scientist nodded. Without hesitation he explained his scheme. Steckel listened intently, his eyes narrowed.
"So you see," Mortenson finally concluded, "we can make it mighty hot for the killer if I get the support of your department. It will be an exceptionally dangerous adventure, but worth...."
"Then count me in personally!" Steckel injected quickly. "If we can lay our hands on the phantom bandit by going into the Fifth Dimension after him, it will be worth the chance we take. When you are ready I'll detail eight men to your services. Moreover, the department will stand the expense of duplicating your apparatus ... ten complete sets. I think it would be well to start immediately, don't you?"