“That’s right.” Arthur stepped over and adjusted Cole’s grip on the handle. “Buckminster Fuller came up with the design hundreds of years ago. Well, sorta.” He ran his hand down the wooden approximation of a blade while he talked. “It’s a single matrix of carbon laced with iron, neodymium, and cobalt. Extremely ferromagnetic, okay? Super sharp. But the trick is in the blade’s handle, that’s where the electromagnetic field is created that spools the wire out and keeps it stiff. The blade’ll cut through damn near anything.”

“Even each other?”

“Sharp kid,” Arthur said, looking at Penny and jabbing a thumb his way. She shrugged and twirled her stick in a graceful pattern, so fast Cole could hear the air screaming in protest as it tried to move out of the way.

“No, not each other. Buckblades have orthogonal magnetic charges, otherwise they’d fly out of your hand and stick to something metal, get it?”

“Orthogonal?” Cole asked. “Is that positive or negative?”

“Neither. There’s two other kinds of magnetic fields, monopoles that can be harvested here in hyperspace. All Buckblades have the same charge, so it’s almost impossible to get them together, much less cut through one another.”

“They fly away from each other? Why not make some of them with the opposite charge, then?”

Cole tried to mimic the pattern Penny was making, which made her laugh.

“You just lost your clever points, son. Now I have to assume you got lucky before.”

“What do you think would happen?” Penny asked, taunting him.

“They’d stick together?”

“That’s putting it mildly, now pay attention. When someone swings at you, you can’t get hit. Not even a little, okay?”

“I think he’s learned that lesson,” Penny said. She darted forward and smacked the back of his right hand with her sword.

Cole dropped his weapon and shook his hand, glaring at her.

“Good point, Penny. Now, Cole, keep a firm grip on your sword.” Arthur bent down, picked it up, and handed it back to him. “Don’t crush the thing, but try not to drop it.”

“Why’d you make the thing feel pain?” Cole asked, rubbing his hand.

“Same reason God made the other one that way. So you’d take care of it. Now listen, you don’t want to get hit. Not once. And you can’t really block your opponent’s attacks, they’ll just repulse each other—”

“How does this work, then? He who swings first, wins?”

“The other way around, usually. See the slits on your sword?”

Cole inspected the wooden blade. There were deep cracks running down the length of the thing. He nodded.

“When you swing the practice swords at each other, internal sensors calculate where they would be repulsed to. Lights in the blade shine out and your suit picks them up—”