"Why do I give it to you? Because it will kill you. You have seen what the stuff will do. A strand a thousandth of an inch thick, encased in silon for lubrication purposes, got me out of that filthy hole you call a prison. You've heard about that?"
Fergus blinked. "You cut yourself out of there with the cable you're talking about?"
"Not with the cable. With a thin fiber. With one of the hairlike fibers that makes up the cable. Did you ever cut cheese with a wire? In effect, that wire is a knife—a knife that consists only of an edge.
"Or, another experiment you may have heard of. Take a block of ice. Connect a couple of ten-pound weights together with a few feet of piano wire and loop it across the ice block to that the weights hang free on either side, with the wire over the top of the block. The wire will cut right through the ice in a short time. The trouble is that the ice block remains whole—because the ice melts under the pressure of the wire and then flows around it and freezes again on the other side. But if you lubricate the wire with ordinary glycerine, it prevents the re-freezing and the ice block will be cut in two."
Tarnhorst nodded. "I remember. In school. They—" He let his voice trail off.
"Yeah. Exactly. It's a common experiment in basic science. Borazon fiber works the same way. Because it is so fine and has such tremendous tensile strength, it is possible to apply a pressure of hundreds of millions of pounds per square inch over a very small area. Under pressures like that, steel cuts easily. With silon covering to lubricate the cut, there's nothing to it. As you have heard from the guards in your little hell-hole.
"Hell-hole?" Tarnhorst's eyes narrowed and he flicked a quick glance at Fergus. Morgan realized that Tarnhorst had known nothing of the extent of Fergus' machinations.
"That lovely little political prison up in Fort Tryon Park that the World Welfare State, with its usual solicitousness for the common man, keeps for its favorite guests," Morgan said. His wolfish smile returned. "I'd've cut the whole thing down if I'd had had the time. Not the stone—just the steel. In order to apply that kind of pressure you have to have the filament fastened to something considerably harder than the stuff you're trying to cut, you see. Don't try it with your fingers or you'll lose fingers."
Fergus' eyes widened again and he looked both ill and frightened. "The man we sent ... uh ... who was found in your room. You—" He stopped and seemed to have trouble swallowing.