“Do you trust him?”

“Well, I—”

“Don’t.”

“Right. Don’t. Okay, here we are.”

“Just drive on in and act normal.”

“Act normal. Riiight …”

Dane felt the car slow, then turn, then roll to a stop. Parmenter rolled down his window, and Dane could hear the beep from the card reader as Parmenter swiped his card through it. A faint mechanical whir told him a gate was opening.

They drove down a ramp to underground parking, the sound of the engine and tires reverberating off the concrete walls. Parmenter pulled into a parking lot and shut off the engine. He gave the area a quick 360-degree sweep, then said, “Okay. We’d better make it quick.”

An entry door was only a few yards from where the car was parked. They ducked through, took an elevator up one floor, went down a bare hallway to a service door, stepped through that to another hallway that led to another door that Parmenter unlocked with his security card.

Inside that door was a cluttered office: a desk piled with blue-penciled computer printouts, stacks of binders and manuals against the wall, two whiteboards filled with incomprehensible formulas, and a computer system with three monitors side by side, each one showing a fluctuating display of columns, numbers, graphs, and vaporous, undulating shapes.

Parmenter rolled a chair from a corner. “Have a seat.”

Dane settled in, appreciating all the scribblings on the whiteboard—even if Parmenter had faked all of it, it was still impressive.

“That’s our bottom line, I suppose,” the scientist said, waving a felt tip marker at the whiteboard. “I reworked it several times, from several directions, and every time I landed on one conclusion.” He sighted down the marker at some scribblings in the lower right corner of the second whiteboard, some letters mixed with some numbers and a squiggle sitting on top of some other letters and numbers divided up with slashes and squiggles.

Dane ventured a guess. “Mandy’s in deep soup.”

“Well, we all are, but she is at the heart of the problem. Her reversion was so vast—forty years, several hundred miles!—that her gravitational leverage on the Machine is insurmountable. We can’t counter it. She’s controlling the Machine, using all its power and capability to perform her magic.” He scanned the scribblings for help, but then just said it. “And to maintain her secondary timeline, the very thing that keeps her forty years behind the rest of us. But it’s not without cost. The deflection necessary—”

The other door to the office opened and a younger man, with black curly hair, stepped in. Parmenter rose to make the introduction. “Dane Collins, may I introduce my associate and project manager, Dr. Loren Moss.”

Dane rose and shook the man’s hand. There were no smiles.

“Loren, I was just about to tell Dane about the deflection debt, how it forced retracings of the other subjects.”

Moss nodded and addressed Dane. “Every reversion, every time we shift a timeline or create a new one, we bend space just a little more. It’s like bending a spring; the more you bend it, the more it resists, until you just can’t add any more strain without removing some first. We call that deflection debt. We can’t place any more stress on the universe without relieving some first.”

Parmenter continued, “The rats were so small and the reversion so brief, just a matter of minutes, that the deflection debt was negligible. Monkeys were larger and had greater mass, so they required a little more. The human subjects had far greater mass and required much longer reversions—some a day or two, the soldier—”

“Seven days,” said Moss.

“One of our own staff—”

“Me,” Moss offered. “Fourteen months.”

“Followed by Ernie Myers who only required a three-hour reversion; we reverted him back to the instant he fell from his ladder so he’d remember the fall but not remember being injured. It worked—the first time. Doris Branson, the same thing. We reverted her to the moment of her car accident so the last thing she remembered was losing control of the car. That was four hours. But it was adding up. Our readings indicated a building imposition on the space-time fabric and we were wondering how much more strain we could impose before we reached our limit.”

“I think Mandy put us there.”

“Absolutely,” said Parmenter, referring to the computer monitors. “Not that it’s her fault, of course, but the deflections she imposed were so severe that the space-time fabric began to cast off the earlier deflections. I imagine that little toy block has retraced by now …”

“It’s like a ship that’s too heavy,” said Moss. “If you still want to load more cargo you have to unload something else first.”

“So our little toy car broke into pieces again, our restored pop can squashed again, the rats all retraced, and then the monkeys—” Parmenter leaned toward the monitors. “Wait, hold on.”

Hold on?Dane was about to pounce with a question and now Parmenter was saying “Hold on”? Dane held his peace; it looked serious.

Parmenter tapped away at his keyboard, muttering computations to himself. Moss waited patiently, no doubt familiar with how Parmenter operated. At last, alarmed, Parmenter leaned back, blew out a breath, and said, “She’s coming here.”

Moss looked incredulous. “Coming here? You mean … ?”

Parmenter pointed to fields of numbers on the screen, explaining to Dane, “These are space-time axes with corresponding coefficients, designated Kiley, Baker, Delta, blah blah blah; anyway, by looking at the Machine’s readouts I can closely estimate the gravitational influence Mandy is exerting or will be exerting on the Machine over a given span of time, and from that I can calculate her distance from the Machine, and in … forty-three minutes, five seconds, she and the Machine will be no more than two meters apart, which means she’s going to be here in this lab, which means we—most especially you—are going to have some real convincing to do if we hope to save her life.”

Those last three words! “I’m listening. You were talking about the monkeys.”

“They retraced.”

“What does that mean?”

Parmenter looked at Moss, who just looked back at him. Parmenter took it. “Retrace, retrace, uh, it means … in order to revert someone, we have to reverse them on their own timeline—rewind their life, so to speak. But if that’s all we did, then they would simply retrace the same timeline and go through the same accident, injury, whatever, all over again. That’s why we create a secondary timeline, one with an open future that hasn’t been lived yet. When we place the subject on the new timeline, they effectively bypass whatever calamity befell them on their old timeline and continue living as if it never happened. That’s the whole object.”

“But you had to burn the monkeys.”

Parmenter was a little surprised. “I suppose Mandy told you about that.”

“She did.”

“They died. Their reversions failed because their secondary timelines failed and they fell back into their original timelines and retraced.”

“And that was largely due to the load Mandy placed on the space-time fabric,” said Moss. “Any secondary timelines prior to her reversion became unstable.”

Parmenter spoke for his associate. “Loren’s secondary timeline was disrupted when Mandy came through the lab on a tertiary corridor—”

“We have less than forty minutes, Doctor,” Dane reminded him.

“She’s been here before—well, not completely here, maybe half here and half wherever else she was. That’s how she knows about the monkeys.” Parmenter rolled his eyes at his own verbal morass.

Moss stepped in. “Mandy can generate additional timelines and pass into and out of them. It’s how she can see and be in several different places at the same time. It’s how she levitates, how she moves from one place to another and makes objects move and multiplies objects, including herself. I’m sure she doesn’t know how she does it.”