Billy was unaware of it. Billy simply breathed. The nanomechanisms, small as viruses, were absorbed into his bloodstream through the moist fabric of his lungs. As their numbers increased to critical levels, they commenced their work.

To the cybernetics Billy was a vast and intricate territory, a continent. They were isolated at first, a few pioneers colonizing this perilous hinterland along rivers of blood. They read the chemical language of Billy’s hormones and responded with faint chemical messages of their own. They crossed the difficult barrier between blood and brain. They clustered, increasingly numerous, at the interface of flesh and armor.

Billy inhaled a thousand machines with every breath.

The exit loomed ahead of him now, an open doorway into the year 1989.

Billy hurried toward it. He had already begun to sense that something was wrong.

Twenty

Tom was out of bed as soon as the alarm registered. Joyce reached the door ahead of him.

The machine bugs had assembled these alarms from a trio of hardware-store smoke detectors. The noise was shrill, penetrating. Tom and Joyce had slept in their clothes in anticipation of this; but the actual event, like a fire or an air raid, seemed unanticipated and utterly unreal. Tom stopped to fumble for his watch, working to recall what Ben had told him: If the alarm sounds, take your weapon and go to the perimeter of the property, but mainly he followed Joyce, who was waving impatiently from the door.

They hurried through the dark of the living room, through the kitchen and out into a blaze of light: fifteen sodium-vapor security lights installed in the back yard, also courtesy of Home Hardware.

Beyond the lights, in the high brush and damp ferns at the verge of the forest, he crouched with Joyce—and Doug and Catherine, who had beaten them out of the house.

The alarms ceased abruptly. Cricket calls revived in the dark of the woods. Tom felt the racing of his own pulse.

The house was starkly bright among pine silhouettes and a scatter of stars. A night breeze moved in the treetops. Tom flexed his toes among the loamy, damp pine needles: his feet were bare.

He looked around. “Where’s Ben?”

“Inside,” Archer said. “Listen, we should spread out a little bit … cover more territory.”

Archer playing space soldier. But it wasn’t a game. “This is it, isn’t it?”

Archer flashed him a nervous grin. “The main event.” Tom turned to the house in time to see the windows explode.

Glass showered over the lawn, a glittering arc in the glare of the lights.

He took a step back into the shelter of the woods. He felt Joyce do the same.

But there was no real retreating.

Here was the axis of events, the absolute present, Tom thought, and nothing to do but embrace it.

Twenty-One

Ben stood calmly in the concussion of the grenade. It was an EM pulse grenade, less useful to the marauder than it had been; the cybernetics were hardened against it. The blast traveled up the stairway from the basement and exploded the windows behind him. Ben felt the concussion as a rush of warm air and a pressure in his ears. He stood with his back to the door, braced on his one good leg, watching the stairs.

He didn’t doubt that the marauder could kill him. The marauder had killed him once and was quite capable of doing so again—perhaps irreparably. But he wasn’t afraid of death. He had experienced, at least, its peripheries: a cold place, lonesome, deep, but not especially frightening. He was afraid of leaving his life behind … but even that fear was less profound than he’d expected.

He’d left behind a great many things already. He had left his life in the future. He had buried the woman he had lived with for thirty years, long before he dreamed the existence of fractal, knitted time. He wasn’t a stranger to loss or abandonment.

He had been recruited at the end of a life he’d come to terms with: maybe that was a requirement. The time travelers had seemed to know that about him. Ben recalled their cool, unwavering eyes. They appeared in human form as a courtesy to their custodians; but Ben had sensed the strangeness under the disguise. Our descendants, he had thought, yes, our children, in a very real sense … but removed from us across such an inconceivable ocean of years.

He listened for the sound of footsteps up the stairs. He hoped Catherine Simmons and the others had deployed outside the house … fervently hoped they wouldn’t be needed. He had volunteered to defend this outpost; they had not, except informally and in a condition of awe.

But the nanomechanisms were already doing their work, deep in the body of the marauder: Ben felt them doing it.

Felt them as the marauder came up the carpeted stairs. Ben watched him come. The marauder moved slowly. His eyepiece tracked Ben with oiled precision.

He was an amazing sight. Ben had studied the civil wars of the twenty-first century, had seen this man before, knew what to expect; he was impressed in spite of all that. The hybridization of man and mechanism was mankind’s future, but here was a sterile mutation: a mutual parasitism imposed from without. The armor was not an enhancement but a cruel prosthetic. Infantry doctors had rendered this man incapable of unassisted pleasure, made his daily fife a gray counterfeit, linked every appetite to combat.

The marauder, not tall but quite golden, came to the top of the stairs with small swift movements. Then he did a remarkable thing:

He stumbled.

Dropped to one knee, looked up.

Ben felt the nanomechanisms laboring inside this man. Vital connections severed, relays heating, redundancies overwhelmed … “Tell me your name,” Ben said gently.

“Billy Gargullo,” the marauder said, and fired a beam weapon from his wrist.

But the marauder was slow and Ben, augmented, anticipated the move and ducked away.

He fired his own weapon. The focused pulse, invisible, seemed to pull Billy Gargullo forward and down; his armor clenched around him like a fist. He toppled, convulsed once … then used his momentum as the armor relaxed to swing his arm forward.

This was a gesture Ben had not anticipated. He dodged the beam weapon but not quickly enough; it cut a charred canyon across his abdomen.

Ben dropped and rolled to extinguish his burning clothing, then discovered he couldn’t sit up. He had been cut nearly in half.

Precious moments ticked away. Ben felt his awareness ebb. A wave of cybernetics poured out from the walls, covered the wound, sealed it; severed arteries closed from within. For a brief and unsustainable moment his blood pressure rose to something like normal; his vision cleared.

Ben pushed himself up on his elbows and fumbled for his weapon.

He found it, raised it …

But Billy had left the room.

Twenty-two

By the time he reached the foot of the basement stairs Billy assumed he was dying.

He knew his armor was crumbling away, somehow, inside him. His eyepiece displayed bright red numerals and emergency diagnostics. He felt cut loose from himself, afloat, hovering over his own body like a bird.

This was very sudden, very strange, unmistakably hostile. He didn’t let it slow him down.

He came up the stairs still operational but awash in strange emotions: vivid lightnings of panic; blue threads of guilt. Billy was coherent enough to understand that he’d walked into a trap; that his prey, the time traveler, someone, had interfered with his armor. There was a perpetual high-pitched keening in his ears and the diagnostics in his eyepiece read him a catalogue of major and minor malfunctions. So far, the gland in the elytra was still pumping—though fitfully—and his weapons were functional. But he was vulnerable and he was slow and before long he might be altogether helpless.