"All I know," Saunders said softly, "is that anything the universe allows us to do will eventually be done. If we don't build the machine, someone else will. Someone who might not hesitate to use it for the mass destruction you're so worried about."
Garwood shook his head tiredly. The discussion was finally turning, as he'd known it eventually would, onto ail-too familiar territory: the question of whether or not the fruits of Backdrop's labor would be used responsibly by the politicians who would inherit it. "We've gone round and round on this one," he sighed, getting to his feet. "Neither of us is likely to change the other's mind this time, either. So if you don't mind, it's been a long drive and I'd like to get some rest."
"Fine." Saunders stood, too. "Tomorrow is soon enough to get back to work."
In the distance, the sound of more cracking plaster underlined his last word. "And if I refuse?" Garwood asked.
"You won't."
"Suppose I do?" Garwood persisted.
Saunders smiled lopsidedly and waved a hand in an all-encompassing gesture. "You talk too contemptuously about the not-me' generation to adopt their philosophy. You won't turn your back on a problem this serious... especially given that it's a problem partially of your own creation."
For a long moment Garwood considered arguing the latter point. It had been Saunders, after all, who'd pushed Backdrop into existence and then dragged him into it.
But on the other hand, it wasn't Saunders who knew how to build the damn time machine.
Wordlessly, he turned his back on the other and headed for the door. "Rest well," Saunders called after him.
—
His office, when he arrived there the next morning, was almost unrecognizable.
Two pieces of brand-new equipment had been shoehorned into the already cramped space, for starters; a terminal with what turned out to be a direct line to the Minneapolis Cray HI supercomputer lab, and an expensive optical scanner that seemed set up to read typewritten equations directly onto the line. So Saunders is capable of learning, Garwood thought sardonically, careful not to touch either instrument as he gave them a brief examination. The electronic blackboard that had fallen apart shortly before he left Backdrop was gone, replaced by an old-fashioned chalk-on-slate type, and his steel-and-plastic chair had been replaced by a steel-and-wood one. Even his desk looked somehow different, though it took him a long minute to realize why.
All the piles of papers had been changed.
Silently, he mouthed a curse. He hadn't expected the papers to remain untouched—Saunders would certainly have ransacked his desk in hopes of finding the rest of his time-travel equations—but he hadn't expected everything to get so thoroughly shuffled in the process. Clearly, Saunders had gone about his task with a will and to hell with neatness; just as clearly, it was going to take most of the day to put things back where he could find them again. With a sigh, he sank gingerly into his new chair and started restacking.
It was two hours later, and he was not quite halfway through the task, when there was a knock on the door. "Come in, Saunders," he called.
It wasn't Saunders. "Hello, Dr. Garwood," Major Davidson nodded, throwing a glance around the room. "You busy?"
"Not especially." Garwood looked up at him. "Checking to make sure I'm still here?"
Davidson shrugged fractionally, his gaze steady on Garwood. "Not really. I believe Colonel Bidwell has been able to plug the hole you got out by the last time."
"I'm not surprised." The look in Davidson's eyes was becoming just the least bit unnerving. "May I ask why you're here, then?"
Davidson pursed his lips. "The random destruction has started up again since we got in last night."
"This surprises you?"
Davidson opened his mouth; closed it. Tried again. "I'd... rather hoped you weren't so clearly the pivotal point of the effect."
"I thought we'd discussed all that back in Champaign," Garwood reminded him. "I'm the only one who knows how to build the machine, so of course the probability-shift effect centers around me."
Davidson's eyes flicked to the computer terminal/optical scanner setup. "And Saunders wants you to let him in on the secret."
"Naturally. I don't intend to, of course."
"And if he doesn't give you that choice?"
"Meaning...?"
"Meaning he tried once to use hypnosis to get your equations out of me. With you, the method would probably work."
Garwood's mouth felt dry. "He knows better than to try something that blatant," he said. Even to himself the words didn't sound very convincing.
"I hope so. But if he doesn't... I trust you'll always remember that there's at least one other person in Backdrop who recognizes the danger your knowledge poses."
Garwood nodded, wishing he knew exactly what the man was saying. Was he offering to help Garwood escape again should that become necessary? "I'll remember," he promised. "You're going to be here for awhile, then?"
Davidson smiled wryly. "They let me out on a tight rein to go after you, Doctor. That doesn't mean they want me running around loose with what I know about Backdrop. I'll be on temporary duty with the security office, at least for the foreseeable future." He paused halfway through the act of turning back toward the door. "Though I don't suppose the term 'foreseeable future' has quite the same meaning as it used to, does it?"
Without waiting for an answer, he nodded and left. No, it doesn't, Garwood agreed silently at the closed door. It really doesn't.
He thought about it for a long minute. Then, with a shiver, he turned back to his papers.
—
One by one, the leads faded into blind alleys... and two months later, Garwood finally admitted defeat.
"Damn you," he muttered aloud, slouching wearily in his chair as far away from his terminal as space permitted. "Damn you." An impotent curse hurled at the terminal, at the program, at the universe itself. "There has to be a way. There has to be."
His only answer was the vague and distant crash of something heavy, the sound muffled and unidentifiable. A piece of I-beam from the ceiling, he rather thought—the basic infrastructure of Backdrop had started to go the way of the more fragile plaster and electronics over the past couple of weeks. Saunders had spent much of that time trying to invent correlations between the increase in the destruction with some supposed progress in Garwood's mathematical work, and he'd come up with some highly imaginative ones.
But imaginative was all they were... because Garwood knew what was really happening.
Perversely, even as it blocked his attempts to find a safe method of time travel, the universe had been busily showing him exactly how to transform his original equations into actual real-world hardware.
It was, on one level, maddening. He would be sitting at his typewriter, preparing a new set of equations for the optical scanner to feed into the computer, when suddenly he would have a flash of insight as to how a properly tuned set of asynchronous drivers could handle the multiple timing pulses. Or he'd be waiting for the computer to chew through a tensor calculation and suddenly recognize that an extra coil winding superimposed on a standard transformer system could create both the power and the odd voltage patterns his equations implied. Or he'd even be trying to fall asleep at night, head throbbing with the day's frustrations, and practically see a vision of the mu-metal molding that would distort a pulsed magnetic field by just the right amount to create the necessary envelope for radiating plasma bursts.
And as the insights came more and more frequently—as a working time machine came closer and closer to reality—the environment inside Backdrop came to look more and more like a war zone.