“Meaning I float at a full stop.”

“Well, as you know, equilibrium won’t cancel out momentum you already have. To slow down you need to reverse direction of descent momentarily.” She looked him up and down. “You ready to give it a try?”

He tugged at the nylon harnesses holding him in place. They seemed secure. “Sure. How much trouble can I get in?”

Cotton chuckled. “Famous last words.”

“Start out by pulling the right controller all the way back. I want your gravity field to be as narrow as possible. That’ll make it just above your height.”

Grady used his toes to pull the controller back. “So a roughly six-foot sphere around me will be subjected to my gravity field.”

“Right. In fact, do press the button to lock that setting. We don’t want you accidentally expanding the sphere and bringing a wall down on us.”

He clicked the button and tried nudging the slider. It was locked down fast. “Okay. I got it. It’s locked.”

“Now pull back on the left controller to set it to equilibrium. That way you won’t fly off anywhere.”

He did so and nodded.

“Okay. Let’s power it up.”

Grady hesitated a moment before studying his gauntlets for the control interface. The boots and gauntlets apparently had power sources of their own and were paired via a q-link to the harness—and presumably to the rest of the assault armor, had it been present. In a moment Grady remembered how to make a pop-up holographic control panel appear above his arm.

Alexa pointed. “Remember not to go into this interface while you’re airborne. Never power down while in the air.”

“Got it.” He tapped the master power switch.

And suddenly felt like he was in free fall. His stomach lurched as if he’d plunged down the first hill on a roller coaster. He pushed off slightly from the concrete floor and moved upward until the nylon straps restrained him.

Grady felt a smile spread across his face, and he laughed. “This is really incredible!”

Cotton stood next to Alexa now, watching. “They really must have messed with his head in that prison.”

Alexa waved to get Grady’s attention. “Okay. Now I want you to experiment with directional control. Don’t do it at full gravity—we can’t trust these straps or the beams in an old building like this. So choose your direction of descent with both feet . . .”

Grady concentrated and chose a direction to the left—toward an open space of lab.

“Good. Now slowly push forward on the left controller to bring yourself up to a quarter gravity.”

Grady took a deep breath and nudged his toes forward against the control. He suddenly felt a physical manifestation of the natural forces of the universe reaching out to him, tugging him to the left—which had now suddenly become a wholly convincing “down.” A glance at Alexa and Cotton made it seem as though they were standing on the face of a concrete cliff, while the workshop floor stretched down in a sheer drop to a brick wall a hundred feet below. “My God!”

The nylon straps restrained him from continuing, and he hung like a bug in a spiderweb until he could get his heart rate to come down.

“You look a little red-faced, Jon. You all right?”

He laughed. “Yeah. Beautiful! It’s amazing. Just gotta wrap my head around it, that’s all.”

Grady changed the direction of down without changing the intensity of gravitation, and the angle of down swept across his horizon like the sun rising and setting. The straps and beams creaked.

“Just miraculous . . .” He experimented a bit more, flexing the nylon straps first one direction and then another. Finally he looked up at them and nodded. “I’m ready for a free flight, I think.”

Alexa looked grim. “Be careful, Jon. You can easily kill yourself with this equipment—especially in a room this size. It could be a hundred-foot fall right into a brick wall—and then you might collapse the brick wall, if you’re not careful.”

He took a deep breath and reviewed his familiarity with the controls. “No. No, I think I’ve got this. Worst-case scenario, I just pull back with my left toes on the controller, and I go into weightlessness. Right?”

She nodded. “Right. Remember that if you get into trouble.”

Cotton frowned. “It’s a bit more than that. Weightlessness is all well and good, but watch the direction of down near walls and furniture. They were designed with a pretty boring direction for down in mind, so don’t go wrecking anything.”

“Don’t worry. I’ve got this. Hell, I invented this.”

“Let’s not get cocky.”

“Here, I’m going into equilibrium. Start undoing the straps.”

Alexa stepped forward, keeping most of her body weight outside the altered gravity field as she started unfastening the straps from Grady’s gravis. In a few minutes he was floating free.

“Ha, ha!” Grady flexed his arms and started doing a Russian folk dance in midair. “Hey! Hey! Hey!”

“All right. Enough of that. Try to move toward that doorway.”

Grady did one last “Hey!” and then he directed his right foot toward the target. He concentrated, and then, keeping his left foot level, he slowly ramped up the force of gravity.

Too fast—he was already falling at thirty miles an hour toward the doorway.

“Left foot! Pull back!”

Grady gripped the left nodule controller with his toes and brought it back to zero gravity—but his momentum kept him going forward at a considerable clip.

In a moment of clarity, he twisted his right foot and ramped up the gravity slightly in that direction, turning in an arc back the way he came—like an ice skater burning off momentum by digging in his skates.

“Watch the shelving!”

Grady just barely bumped the shelving unit as he came to a stop—while the new direction of down caused one shelving unit to lean sideways, spilling everything off its racks. Grady immediately pulled back into a gravity equilibrium, and all of the items on the shelves started floating—lots of small valves and electronic components.

Cotton grabbed his head with his hands. “For fuck’s sake! Look at the mess you’re making.”

Alexa nodded encouragement. “That was good thinking, Jon. Your knowledge of physics is going to help you here. Newton’s first law. Uniform motion.”

Grady nodded. “Right.” He patted the shelf in front of him. “Thanks, Isaac.”

“Now try it again.”

Cotton added, “And this time try not to almost kill yourself.”

Grady ran through his knowledge of the controls again and mimed his planned actions. He finally looked up. “All right. I got this.” He looked across the room toward the doorway, then pointed. “I’m heading right over by the entrance.”

“Not too close. The doors might fall through.”

“Okay. I’ll stop ten feet away.”

“You sure you’re ready?”

He clapped his diamondoid-armored gauntlets together. “Hell, yeah!”

Cotton mumbled to Alexa. “I don’t think I can watch this.”

“O ye of little faith, Cotton.”

“You forget who I was until recently.”

Grady took a deep breath and then altered the direction of descent. This time he gradually increased the force with his left toes, pushing forward only slightly. He began to glide above the floor, some of the debris falling along with him, scraping on the concrete as it did.

“Well, now you’re just scattering the mess around.”

Grady concentrated on the door as he maintained a steady five-mile-per-hour pace. He called back, “I can see it now. You’ve got to have a very fine touch in close spaces.”

Alexa nodded. “Right. You’re doing excellent.”

“You really have to be careful what you get near. Otherwise you quickly get a cloud of debris around you.”

In a few moments, Grady eased back on the controller, and this time, he lowered his pitch until he could drag his foot along the floor. In a moment he leveled it out and came to a standing stop almost exactly ten feet away from the doorway. He then put himself into half gravity with down being down. Locking gravity, he turned to face them, arms spread wide. “What do you think?”