A Bridge of Years

But he couldn’t live with the knowledge that they might still find him—the time travelers, the tu

Therefore, he could fight.

True, he didn’t know who or what the intruder might be. But maybe that was only a temporary difficulty. Much of his armor’s forensics were still working; Billy guessed he could learn a great deal if he examined the tu

It all depended on the armor, didn’t it?

His lifeline. His life.

At last, he took it out of its hiding place.

He had traded its cardboard box for a wooden chest of approximately two cubic feet in volume—he’d found it in a Salvation Army thrift shop. The chest was closed with a padlock. Billy placed great faith in padlocks; they seemed so much more substantial than the electronic locks of his own era. He wore the key attached to a belt-loop of his pants. Billy lifted the chest from the back of his closet and used the key to open it.

The holes where the lancet and the stylet entered his body had almost healed—but it only hurt for a minute.

He wore loose, layered clothing over the armor to conceal it.

Billy knew how this made him look. He looked like an alcoholic, a bum. Seeing him, people would turn their faces away. But that wasn’t a bad thing.

Underneath, the armor regulated his skin temperature, kept him cool, kept him alert.

The armor was “turned off”—well below full combat capability. But its regulatory functions were automatic. The armor sampled his blood, his nervous impulses. A gland in one of the elytra synthesized new hormones and drip-released them into his body. He was alert, happy, confident.

He was awake.

Life is sleeping, Billy thought. The armor is waking up. Fu

All his doubts dissolved. He felt the way he imagined a wolf must feel: fiercely focused and dizzy with the pleasure of the hunt.

He went to the building where his pensioners lived, at the junction of time and time.

He installed two new locks he’d bought at a hardware store yesterday: a new knob set for the door in the lobby and a new padlock for the door farther down. If one of the tenants happened to see him while he was working Billy was prepared to offer an excuse for the way he was dressed—but no one came by except a delivery boy with a box of groceries for Amos Shank, up the stairs and out again without speaking.

Then Billy was in the basement, where no one ever went.

He installed the new padlock and hooked the key to the loop on his belt. Now Billy jingled when he walked.

Then he followed the stone stairs down to the lowest level of the building, the sub-sub-basement where the tu

He didn’t like coming down here. Armor or not, he didn’t like the tu

Was it a time ghost that had come after him now?

Billy didn’t think so. A

He clambered over the scattered rubble into the mouth of the tu

Sneaker-prints.

There was a great confusion of these prints and Billy wondered—nervous in the brisk, pale light of the tu

But no—the lock on the door had been broken from the inside.

Someone who had stumbled onto the tu

That was possible—even encouraging. Billy had assumed that gateway was all but unusable; still, after a decade, he supposed someone might have opened it somehow. This new possibility made him more optimistic. He would have to hunt the intruder down and kill him, of course; he needed to be the tu

Still, he shouldn’t count on that. Prepare for hard battle, hope for a vulnerable target.

He cast a final glance down the empty tu

He was able to learn a great deal.

His armor detected and memorized fingerprints from the cellar walls, skin samples where the intruder had cut himself on a shard of glass projecting from the rubble. The intruder was quite human, a male, type 0+ blood. Back home, a competent laboratory might have been able to put together a portrait of the man from a simple genome projection, assuming the samples were more or less intact. But Billy didn’t have that capacity; he needed another means of tracking his prey.

The enormity of the task was daunting. It might be impossible—a civilian joyriding from the future might be anywhere. Might have jumped a plane to some familiar place. Invested money in the stock market and set off on a tour of his own recent history.

But the man had arrived here less than a month ago and Billy guessed he would need more time than that to adjust. After all: his money was no good, his knowledge was valuable but difficult to cash in on. He might still be close by.

But how to identify him?

Billy ran a finger through the dust on the floor. Dust from his concussion grenade, dust from the foundation of the building. He opened a pouch in one of the elytra of his armor and withdrew the armor’s headset, a leathery black mask that covered his face entirely. He clipped an optical cable between the headset and the armor’s processors while his forensics sampled the dust and a

Billy narrowed the bandwidth of his eyepiece to the frequency of strongest emission, then clambered back into the dark chamber of the basement.

With his opticals adjusted, the dust was plainly luminescent.

He stood in a starry blue limbo, very strange. The tip of his forefinger radiated light like a small constellation.

How much of this dust had the intruder carried out of the building? How much would cling to him? To his shoes? To his clothes? For how long?