David Walton - Supersymmetry

“It makes sense of a lot of things. It explains why it wanted to kill us particularly. It also explains why it failed, despite its power—it’s not at its full strength. It’s only partially able to manipulate things in our universe. Not only that, but it explains why it wasn’t able to possess us directly, despite seeming to be able to possess anyone around us and use them to attack.”

“What about your father? The varcolac attacked him first, not you.”

“No, it didn’t. Remember, it killed him by sending a particle back in time.”

“I don’t understand.”

“My dad knew about the standing wave. If we’re right, he knew it was what was keeping the varcolac out. What if he figured out a way to delay its collapse or even strengthen it? It would have preserved us—me—as two different people, and it would have kept the varcolac away. But then, what if after he did so, the varcolac had to attack in a different way, by sending the Higgs singlet back in time to kill him before he figured it out in the first place?”

Angel held her gaze intently. “Let’s say that’s right. What happened to the original timeline? In which your father defeated the varcolac and preserved you as two separate people?”

Alessandra pressed her lips together and shook her head. “It was destroyed. Erased. A new history began with the stadium disaster.”

“How do you know?”

She shrugged. “I don’t entirely know. But the multiverse theories have always been a bit fanciful. It’s hard to believe that entirely new universes are being created all the time, whenever any particle’s probability wave collapses. The math certainly doesn’t require it. Remember Ryan’s illustration with the billiard balls? There’s only one timeline. The universe solves the equation so that causality is preserved.”

“You’re saying that it creates a loop? That the changed event in the past causes a situation that results in the particle being sent back in time to change the past?”

“Pretty much. Not in the same way, necessarily, but somehow a sequence of particles will cause that one to be created and sent back with the exact properties needed to cause this timeline. It sounds crazy, but the math works out. The solutions are possible, and the universe finds them.”

“What would happen if we sent a particle back in time to smash into the varcolac’s particle, and we stopped it from destroying the stadium and killing your father?” Angel asked.

Alessandra gave a rueful smile. “We would all die.”

“What? What do you mean?”

“This timeline, in which you are I are living, would be erased. We would cease to exist—to have ever existed. Time would be recreated from that point forward. The stadium would never have been destroyed. My father would live, perhaps long enough to defeat the varcolac, but you and I would never know it.”

“What do you mean? We would still be alive, too.”

“No. Other very similar people named Angel and Sandra and Alex would still be alive. But they wouldn’t be us . They wouldn’t have our memories or experiences. They would be as different from us as Sandra and Alex were from each other. Different options, different choices, different people.”

Angel’s forehead wrinkled at the thought. “I see what you’re saying,” he said. “I wouldn’t have thought of it that way, but then, I haven’t lived side by side with an alternate me for the last fifteen years.”

“Sandra!” her mother called. Alessandra thought about correcting the name, but she heard the concern in her mother’s voice. Her mother had been sitting in a corner of the lab, reading something on her phone.

“What is it?” Alessandra asked.

“You’d better look at this,” her mother said.

She held up the phone. The news headlines read: NUCLEAR BLAST DESTROYS KRAKOW. WAR DECLARED.

Angel caught her eye. We have to do something , he seemed to say. He was looking to her for a solution. But what could she possibly do?

Over the course of the next three hours, nuclear blasts destroyed the cities of Berlin, Frankfurt, and Istanbul. The president of Turkey went on the air to urge restraint, claiming that his country had not fired any of the weapons. He asked the surviving leaders of Poland, Germany, and the United States to consider a summit to discuss peace accords. Poland and Germany refused. The United States remained silent.

Then Russia, which had so far remained neutral in the conflict, inexplicably fired high-yield nuclear missiles on China’s three largest cities. Shanghai, Beijing, and Guangzhou disappeared before the sun had risen in New Jersey, and a hundred million people died. The Russian premier, looking genuinely horrified, mirrored the Turkish president’s claim that the weapons had not been fired by his government, but it was too late. Ancient globe-spanning hatreds and mistrusts were reignited around the world. Militaries were put on high alert, fleets were launched, and world leaders were evacuated to secure locations.

“It’s the right thing to do,” Angel said. “If it’s at all feasible to send that particle back and change the past, we should. We’re going to die anyway. Humanity itself as a species might not survive. If there’s any possible chance to reverse that, it’s our moral obligation to do it.”

“Think about what you’re saying,” Alessandra said. “Even if it were possible—which, let me tell you, I sincerely doubt—you’re talking about annihilating everyone . Murdering everyone currently alive and replacing them with different versions of themselves, in a brand new timeline. Nuclear weapons can kill millions, but what you’re suggesting would kill everyone.”

“It’s not like that. Except for any children born in the last few weeks, those people would be alive. All the people dying in those cities right now would be alive again. It’s not killing them; it’s saving them.”

“Think of it like a river,” Alessandra said. “We’re floating along downstream. What you’re suggesting would be like damming the river and sending it floating off in a different direction. There would be a different timeline—different people, different events—but it wouldn’t be us. Our whole universe from that point onward would disappear. We would be dead, replaced by a different version of ourselves, living in a similar but different universe.”

“I agree with Angel,” her mother said.

Alessandra turned on her, feeling hurt, but her mother put a hand on her face, momentarily stopping any angry outburst. “You’re wrong. Don’t you feel it? Sandra and Alex haven’t died. They were always the same. They were always you, and they still are. Different careers, different friends; those things were peripheral. It was always you. My daughter. My Alessandra.” She stroked her cheek. “To do this, it won’t be killing anyone. A different version is still the same person.”

Alessandra shook her head. “It isn’t right,” she whispered. “It’s what Jean tried to do. She didn’t like the daughter that genetics had served up for her, so she tried to reshape her. To kill the present version of her daughter in favor of another. How can we make that choice for everyone?”

“The varcolac won’t stop,” her mother said. “You and I were both there. Remember? Kidnapped and trapped by that monster? It won’t stop. It will track down every last human being until there are none left. Preserving the lives of people as they are now isn’t an option on the table.”

“Besides,” Angel said. “Not doing it is choosing for them, too. How many people in big cities right now do you think would prefer we do nothing? Russia has thousands of nukes; the United States nearly as many. If the varcolac can control them, it’ll be a long time before it stops.”