Ivy’s ears were ringing. Or...no, that was the life-support alarm in her exosuit. “Suit, what’s going on?” she asked.
Primary systems online. Welcome back, Ivy.
She shook her head. Where was she? The last thing she remembered was being hit by a van, which didn’t make any sense at all. She had just stepped through the portal when it happened, and there shouldn’t have been a vehicle there. She’d triple-checked the videos on the entry point before she left. Ninety-nine percent of time-travel is research, and she’d done her research. “Mission log,” she croaked.
Hour thirty-three—
“So Grandfather’s in the hospital by now.” 
That is correct.
“Oh, this isn’t good,” she mumbled. If it was hour thirty-three, then it was 10:00 PM of the day after the accident that she’d jumped back in time to prevent. She’d missed that window, but there was still a chance for her to save Grandfather at the hospital. It would be the final such visit in a tumultuous year where he’d already been hospitalized six times due to various accidents and illnesses. This one would kill him unless she intervened. And if he died, his work would die with him—work that, if completed, would save the lives of at least two and a half billion people.
“Where am I? Open my eyes.”
Your eyes are open.
Ivy blinked. There was no change in her vision. “Why can’t I see anything? Enhance optics.”
Optics maximized. There is no light available.
“Turn on exteriors.”
Insufficient power.
“Insufficient—? Great. Just great.” If there wasn’t enough power for exterior lights, the suit wouldn’t last much longer. She stretched out her hands and they stopped abruptly. “Why can’t I feel anything?”
Suit haptics have been sealed to prevent injury from low temperatures.
“Low temperatures? Am I in a refrigerator or something?” Ivy suddenly had an idea about where she might be. “Did I die?” she asked.
Not irrecoverably.
“So I’m in a morgue,” she said. She reached up above her head—or, behind her, really, since she was lying on her back—and felt resistance. She pushed, but nothing gave. “I’m going to need the use of my fingers,” she said.
Cold rushed into her fingertips.
“Oooh, Jeez, you weren’t kidding about the low temperatures,” she said. She felt above her and found the inside of a latch. She grappled with it while her fingers went slowly numb. Finally she heard a click and the door above her head opened. Light spilled into the chamber, blinding her as she clambered out.
“De-enhance optics and restore haptics.”
The suit didn’t respond. The life-support alarm stopped mid-keen.
Insufficient power.
The suit had spent all its resources repairing her body. “Well... well, crap,” she said. She’d never been very good at cursing.
Ivy pulled back the exterior head casement—to an outside observer it would have looked like she was peeling back her face to reveal a duplicate copy underneath. She felt the air on her skin and shuddered. She could almost feel herself getting sick; her immune system wouldn’t know these germs.
She stripped the rest of the suit off until she wore nothing but 2023-compatible street clothes—clothes that she had “borrowed” from her grandmother’s closet back when she was a teenager. The jeans were utilitarian, but she wondered how conspicuous the shirt would be, a bright pink crop top with a giant sunflower on the chest. Well, it was what she had. She retrieved her utility belt and medikit, then crumpled the suit into a ball and tossed it into a nearby dustbin. Depowered, it looked like a wadded-up piece of manila paper. Over the next seventy-two hours it would degrade. By the end of that period, none of the 2071-era technology would be identifiable.
That took care of the suit, but there were larger problems to address, not least that someone had tried to kill her with a van. Ivy didn’t know what to do with that. It should be impossible—no one knew she was here. Who else even had time travel capabilities? Someone from her future, perhaps? But if she was in someone else’s past, what could she do about it? Nothing. Not if her every movement was being recorded somehow—tracked on cameras at ATMs, intersections, building security, and a million smartphones. The same way she had tracked Grandfather. Did they know about her plan? Of course they did. They’d already thwarted it. But did they know about her backup plans?
I guess I’ll find out , she thought. For now, all she could do was get to Grandfather and try to save his life. According to her research, his accident had happened near the McCullough Bridge, and he’d been taken to the ICU at Allegheny General. With luck, Ivy would have been brought to the same hospital. Unless she wasn’t in a hospital at all.
She needed to figure out her current time and location. Normally her suit would be able to provide those, but it was busy decomposing. She wandered out of the freezer room and into an office. The clock on the wall read 10:23. Assuming it was correct, that gave her sixteen minutes. She found some stationary on a table that had the name and address of a funeral home and then breathed a loud sigh of relief when she realized she was on the right side of the river, maybe one and a third miles from the hospital. She could make that distance on foot in sixteen minutes...couldn’t she?
Of course she could. She had to. Two and a half billion lives were hanging in the balance.
Seven minutes into her run, Ivy remembered why she hated running. Every breath was like fire. Her ankles were sore. Even her teeth hurt. And worst of all, she hadn’t thought to wear a sports bra. Everything’s gone to heck , she thought. And of course, if she failed, there was the pill in her medikit that they referred to as Plan Z . Time travel was a one-way trip. Theoretically, if she succeeded, she’d get swept up in a tide of chronal energy as the timeline shifted out from underneath her. But if she failed—or heck, maybe even if she succeeded, this was all theoretical—she had to be prepared to die as soon as possible. The more time she spent in the past, the greater the chances for unforeseen consequences in the future.
But none of that mattered if she didn’t accomplish her mission.
She could see the hospital peeking up from behind a nearby building. How many more blocks left? It couldn’t be more than two, maybe three. Her legs pumped. She flinched at every passing car. She felt naked, running down the street without her exosuit, exposed to the air, to the past, to the ravages of time and history. Run , she told herself. Run for the billions who will die.
The emergency room doors slid open as she approached. The sharp fluorescent lights of the triage and waiting area bit at her eyes. “De-enhance...” she started to say, but trailed off. There were no optic units feeding directly to her pupils anymore. She glanced around the room to get her bearings, as if she hadn’t memorized the blueprint for the building before she left. She approached the admitting station, trying to recover from her run and gaping like a fish. “I’m here...” Wheeze. “...to see...” Gasp. “Ethan Greenbriar.” Cough, cough, cough. “I’m his”—she almost said granddaughter, but caught herself—“his niece...he’s in ICU...I know the room.”
The admitting nurse didn’t even look up. She pushed a button under the desk and went back to her paperwork. Ivy passed into the corridor and made a beeline for the elevator. She looked at the clock on the wall. Grandfather wouldn’t be found dead for another four minutes or so. She considered the stairs. It was potentially faster than the elevator, if her legs didn’t already feel like jelly.
Her thoughts were interrupted by the ding of the elevator car arriving. Ivy entered and rode up to the ICU, a horseshoe of curtained rooms around a busy nurse’s station. Ivy walked past, affecting careless determination, the swagger of someone who had been there before, knew where she was going, and didn’t care to be stopped. She found the room and walked around the curtain. The lights were low. After the brightness of the rest of the hospital, it took a moment for her eyes to adjust, but soon enough she could see him.
There he was. Ethan Greenbriar, the grandfather she’d never met, lying silently, bruised and bandaged all over, tubes in his face. He looked so young. The patches of stubble on his cheeks. The thin blond hair that fell to his eyes. She could hear the repeating beeps of the heart monitor. He was alive. She’d made it. She allowed herself a sigh of relief.
Ivy hadn’t had direct access to her grandfather’s autopsy, but as far as she’d been able to piece together, the cause of death was an air embolism after his emergency surgery. It was an easy thing for a doctor to miss, she supposed. She pulled a small pink capsule from her utility belt. It was the same tech that was in her suit that allowed it to repair her body, but in a much smaller dose. He needed to survive, but a miraculous recovery would draw a lot of unwanted attention. No, she needed her grandfather to go back to his normal life and his normal work so he could discover the cure to Berkel-Haber Syndrome 1—the autoimmune plague that would wipe out at least a third of the human population.
She held the capsule over his nostrils. All she had to do was break it open and pour the contents into his airway. Heck, if only half of it got in, it would be enough. She squeezed.
A ripple of light moved in front of her. Something slammed into her face. The uncracked capsule flew from her hands and skidded across the floor. Another impact took her in the stomach and she stumbled. The ripple of light moved toward her grandfather.
Ivy grunted. A part of the ripple that was shaped unmistakably like a foot hit her square in the eye. She lay there dazed, watching helplessly as it approached her grandfather. She hadn’t been wrong about the foot. With a little more distance, she could see that the whole ripple was in the shape of a human being. It was a person wearing a suit, an exosuit like hers, but with adaptive camouflage. Ivy tried to raise her head.
“Please,” it said in a woman’s voice, “this is hard enough. Don’t make me kill you, too.”
A wave of recognition washed over Ivy, as though she knew this person somehow. “Who are you ?” she asked.
“Who are you?” replied the ripple.
“People will die,” Ivy whispered.
The ripple nodded. “I know,” it said. It pulled a syringe from some unseen pocket and injected air into Grandfather’s IV line. The ripple picked up the pink capsule that Ivy had dropped and pocketed it, then disappeared through the curtain, its footsteps blending in with those of the nurses buzzing around outside the curtain.
Ivy slowly forced herself up to her feet. Her face seethed where it’d been kicked. Maybe if she could get to the nurse’s station on time—but no, they were already running in. She looked at the clock on the wall. 10:39. The time of death on his death certificate.
Someone pulled her out of the room. They didn’t suspect foul play, of course. They barely even noticed her. She was alone outside a room busy with futile activity. She had failed again. But she could not give up. There was one last thing she could try. It was a long-shot, and it wouldn’t save Grandfather, but it would let her get a message to her future self.
But if someone was trying to stop her, someone who knew her plans... They’d thwarted her twice already. Would they know about Grandfather’s diary as well?
Ivy asked the front desk to call her a taxi. It took a while. By 2023, there were hardly any taxis left in Pittsburgh, most of them having been replaced by rideshare apps. Those required a phone with a data plan, and she couldn’t even spoof that without her exosuit. But she had some 2023 cash, so she waited for a taxi. And waited. It took over an hour, but it was still faster than walking.
And it wasn’t as though she were in a hurry. The most time-critical window had passed. Grandmother would be leaving for the hospital soon and would stay there for most of the night, so Ivy would have plenty of time to use her key to enter the house and alter Grandfather’s diary to leave better notes for herself in the future, so she could try to do better in the next life. After that, she had over a day to make it to the warehouse where she would go to die. The building would shortly be engulfed in a sinkhole, leaving no trace of her body behind until well after 2071.
She gave the cabby the address of her grandmother’s home. She’d visited that home many times on family vacations. It would be weird to see it now, at a time when it was considered modern. The cab crawled through the streets at a pace that Ivy felt was painfully slow but also fitting. She had spent her whole life being too slow. Not only had she been too late to save her grandfather’s life—twice—but she’d been too slow to finish his research. She’d only gotten his diary in 2069, after her father found it while cleaning out Grandmother’s home. That diary had insights into the direction Grandfather would take to cure the plague—a stroke of genius involving a vaccine delivered via retrovirus. It had taken a month to make it work in monkeys and a year of accelerated trials. They were just going into large-scale production when the BH-1 virus he was trying to cure mutated and went airborne.
That’s why she had to save him. He could have developed the vaccine in his own lifetime. But instead he lost his grip on life and the newly airborne plague ravaged the world. Billions died in a matter of months. And it was unlikely that the remaining billions would hold out much longer. 
Ivy would already be dead too if she hadn’t been on the university campus when the lockdown happened. And she’d still be there trapped in the future if she hadn’t been in the same building as Dr. Eliza Shuul, head of the Wormhole Physics department. And if Dr. Shuul hadn’t already had success sending microbes back into the near past. And if Ivy hadn’t been able to convince her to try something more ambitious, such as this Hail-Mary attempt to save all of humanity.
And it had worked. Amazingly, against all odds, Ivy had been lucky. Lucky, but too slow. Too slow to save the world. Too slow to outsmart whoever had come back in time to stop her. Ivy sighed, leaning her head against the glass. Who were they? Why did they want two billion people to die? What kind of evil force sent them back just to commit a mass murder so heinous that it would make Hitler blush? And why had they spared her? “Don’t make me kill you, too,” the ripple had said. Had it just been her imagination, or had it sounded...sad?
The cab was nearing the house, and there were flashing lights waiting for them. The police were at Ivy’s grandparents’ house.
“This isn’t for you, is it?” asked the cabby.
Ivy sat up. “No,” she said out loud. She couldn’t get caught. It would undo so much. They’d already have her fingerprints on file as a Jane Doe when they took her to the morgue. Those wouldn’t match anyone, and if a computer in 2071 did match her fingerprints against a fifty-year-old Jane Doe, it would assume that the connection was pure coincidence. But if they caught her now, in this timeline, they’d know she was the same Jane Doe and they’d take her in for questioning. Everything would be ruined. “Keep going,” she said to the cabby.
“You don’t want to—”
“Just keep going.”
The driver frowned. “To where?”
There was only one place. The warehouse. She gave the cabby the address. What else could she do?
“You in some kind of trouble, miss?”
“No more than anybody else,” she answered.
“That’s...quite a shiner you’ve got there. Do I need to call someone?”
Ivy touched a finger to her cheek. It hurt. She shook her head. “No,” she said. “But thank you.”
She leaned against the glass once more. She was in trouble. The whole human race was in trouble. She shivered. She should have worn a long-sleeve shirt instead of this stupid sunflower crop top.
She closed her eyes and started to cry.
Ivy paid the cabby and stepped out into the empty parking lot. Weeds were growing through the seams in the concrete. It was a moonless night, and a flickering halogen lamp provided the only light. It seemed like as good a place as any to die.
The taxi’s tires squealed as it sped away and Ivy was alone. She reached into her medikit to retrieve an orange capsule. She’d been assured that it would be painless. She wondered how long it would take. How many minutes from the time she put it into her mouth would she have to sit and contemplate her mistakes. She placed the pill to her lips, but then put it back in her kit.
She would want to make sure she was in the warehouse before taking it, just in case it was fast acting.
A noise from within the warehouse caught her attention. The building was supposed to be empty—of people, at least. Some technical company had dumped a bunch of outdated computer hardware in the building to be recycled. According to her research, no one had set foot in the place for weeks and no one would again before the sinkhole opened beneath it. So who would be in there making noise? Ivy tiptoed to the wall and pressed herself flat against it, then inched her way along the edge to the door.
It was slightly ajar. The security system had already been disabled. She saw a tiny nodule on the door—a frequency emitter that would neutralize the door alarm. It exactly matched the one she had in her utility kit.
They were here. The ripple. Whoever had hit her with a van and then stomped on her face and then called the police to keep her from getting to Grandmother’s house. They were here!
But why had they come here? To die, like Ivy?
Ivy frowned. No you don’t, not before I get some answers. She’d failed her mission, and she was going to find out why. Who was so vile that they’d go back into the past to prevent her from saving billions of lives? What kind of sick future did this person come from?
She pushed the door aside and slipped in. The regular lights were off, but the emergency exit lamps cast pools of light every ten feet or so along a path up the middle of the warehouse. She could see the shadows of boxes lining the walkway, giant open-top cardboard boxes sitting on pallets, haphazardly filled with motherboards and video cards and keyboards.
There was a shape in the distance that looked like a human lying sprawled on the floor.
“No,” said Ivy, aloud. “No, not yet.” She sprinted. Her legs burned from running earlier, but her anger gave her the strength to run again.
It was a black exosuit with red piping—skin-tight and so dark it seemed to absorb the light. It looked similar to how hers had looked without the camouflage systems engaged. Only this one was a little sleeker. It could have been a later model of her own.
The body didn’t appear to be breathing. Ivy knew better than to check for a pulse. The suit would hide any vitals. Even the face was obscured. Ivy pulled up the mask to see the face of her enemy.
Under the mask was a woman’s face. A familiar face.
For a second, the smell of death overwhelmed Ivy and made it impossible for her to understand what she was seeing. She gagged on the stench and covered her face with her arm. Then she dared to take another look.
The face was ashen, the eyes hollow. But the features were unmistakably Ivy’s own. Maybe not her own exactly . The chin was slightly smaller, and this face had a stud in its nose and mole on one cheek—two features that Ivy lacked. But they could have been sisters. They could have been twin sisters.
“What the heck is this?” Ivy asked.
A small electronic voice answered her. Primary systems online. Welcome back, Ivy.
“No...that can’t be.”
Shall I abort self-termination sequence?
What did this mean? Was she fighting...herself? Had she been the one to hit herself with a van? Why? How?
Ivy started beating the corpse. “No!” she shouted. “No, it’s not fair. Why! I have to know why!” As she drove her fists into the body she could almost see the answers, like memories of another life that sat just beyond her reach. A life without the disease. A life where she grew up playing with her grandfather. Then she imagined herself driving a van into another human being at high speed.
She stumbled back and touched her black eye, then winced at the pain. “Oh, fudge,” she muttered. “You did this to me, didn’t you?”
“Actually, that was me.”
Ivy spun around and saw another woman there. She, too, wore an advanced version of the exosuit that Ivy had traveled back in. This woman didn’t look as much like Ivy as the dead body had, but there was a familial resemblance. She had close cropped hair, a deeper voice, and darker eyes. But still, they could easily have been sisters.
“What are you doing here?” Ivy asked.
“My mission is over,” said the woman. “I came here to die.”
“Who are you?” asked Ivy.
“I’m Ivy.”
“You can’t be Ivy,” said Ivy. “I’m Ivy.”
The woman shrugged. “Time travel, right? I guess we’re not exactly the same person, but I am also the oldest daughter of Sonny and Barb Greenbriar, so we get to have the same name. Sorry about the face, by the way.” She seemed a little uneasy on her feet.
“Sorry about the face?” asked Ivy through gritted teeth, “but not sorry about hitting me with a gall-durn conversion van?”
The other Ivy frowned. “Oh, that wasn’t me. You got hit with a van?”
“Well...” The woman swayed and nearly fell. “I don’t feel so bad about stomping you now.”
“Do you need to sit down?” Ivy asked.
“Best not.”
“So who drove into me?”
The other Ivy shrugged again, then pointed to the dead body. “Her, maybe?”
“So your mission...it wasn’t to kill me?”
“Not exactly.”
Ivy gritted her teeth. “What then, exactly? To kill our grandfather?”
The other woman nodded.
Ivy’s blood boiled. She was ready to lay this woman out on the floor—as unstable as the other Ivy seemed on her feet, it shouldn’t take more than a single kick. “I could kill you,” she said.
The other woman stared bullets back at Ivy. “Don’t judge me. I didn’t want to do it. I loved that man.”
“Why did you, then?”
“Because some alternate version of me from another future had gone back in time to save him. He had to die. It broke my heart to do it, but it was my responsibility.”
“Why did he have to die?” Ivy demanded.
“Look, if the future of all humanity hadn’t been at stake—”
“Don’t give me that,” said Ivy. “How does killing a man who cures a deadly disease equate to saving all of humanity?”
“Oh, don’t kid yourself, sweetheart. Berkel-Haber wasn’t that deadly. It wasn’t even Spanish flu.”
“Billions died!” Ivy yelled. “Billions more will die!”
The other Ivy scoffed. “That’s impossible. Even with a long incubation and 90% mortality ratio, there’s no way a fluid-borne illness can—”
“It was airborne,” said Ivy.
The other Ivy swayed. “What?”
“In 2070. It goes airborne. A third of the planet gets infected before anyone realizes what’s happened.”
The other Ivy slid to the ground. “Oh,” she said. “Oh, that’s bad.”
“Now tell me about the end of humanity,” said Ivy, “in your future.”
The other Ivy slouched. “As bad as that disease sounds...the cure is worse. The retrovirus Grandfather used as the basis of his vaccine...” The other Ivy was sliding farther and farther down to the ground as she spoke. “It affected meiosis. But not in the people who received it, only their children. On top of which, it was sexually transmitted, but had no external symptoms. There was no way of knowing. But if you got the vaccine, or if you had unprotected sex with someone who had, then your children would be completely, irreversibly sterile.”
Ivy blinked. “How many...how many were affected?”
“We’ve been scouring the earth to find anyone who wasn’t,” said the other Ivy.
Ivy sat down as well and rested her head in her hands.
“Shit,” they said in unison.
Ivy looked at her counterpart. “I have to get word to myself in the future. We have to try something different.”
“Different how?” asked the other Ivy, who was lying down on the ground now.
“I don’t know. Future me can figure it out. But we have to leave a note in Grandfather’s diary—it’s the only way to be sure I’ll get it. Stand up.”
“Um...you’re going to have to do this one on your own, I’m afraid,” said the other Ivy. Her voice was getting weaker.
“Why?” asked Ivy, but she knew the answer as soon as she’d asked the question. “You already took your pill, didn’t you?”
“The mission was complete,” she said. “I’m still sorry about your face.”
Ivy winced. She’d finally found an ally, and now she was about to die. “Can I ask you a favor?” she said.
“You can ask.”
“Can I borrow your suit?”
“It won’t work for you,” said the woman, whose voice was now a thin rasp. “Bonded to my phenotype. You’re too different. Hers might work.” She looked over to the body on the ground.
“Yes,” said Ivy. “Hers might.” She looked back at the other Ivy. “One more thing?”
“Make it...quick...”
“You knew Grandfather growing up. What was he like?”
The other woman smiled. The light was fading from her eyes. Her breathing was slow and labored. “He loved...laughing...and video games...and...dry...red...”
And then silence.
Ivy put a hand on the dead woman’s cheek and felt the warmth of a wave of memories sitting just beyond her reach.
Primary systems online. Welcome back, Ivy.
“Hello, suit. What’s your battery at?”
Twelve percent.
“Wow, you didn’t save any for an emergency?”
I thought you were dead.
“I was,” said Ivy, “but then I remembered someplace I need to be.”
And where is that?
“Over the river and through the woods.”
...I’m not familiar with that address, but I can direct you to the McCullough Bridge.
“We’re going to Grandmother’s house.”
...Your grandmother’s house is not on the other side of the Allegheny.
“I realize that.”
Then why—
“It’s a song, suit. It’s just a...you know what? Let’s just go there.”
Should I request a rideshare?
“No way. You smell like a day-old corpse. We’d just be asking to get arrested. Initiate powered run and try not to burn through your battery until we get there.”
Ivy burst through the door of the warehouse and barreled down the street. It felt good to move, especially since she didn’t have to rely on her own leg muscles. “Enhance optics.”
Enhancing optics for nighttime stealth movement.
Night-vision engaged and world became a bright green vista of warehouses and power lines. The highway was nearby. On the other side of that, a subdivision full of small houses. It was almost six miles to her grandmother’s house, but at the rate her suit was moving, she’d be there in twenty minutes.
She spent the run wondering what kind of a note she’d leave. It couldn’t be obvious—if the note said something like “Ivy: I’m from the future!” her future self never would take it seriously. But it also needed to stand out enough that she saw it quickly. And what should she even hint at? Maybe some musings about the potential dangers of retroviruses that hadn’t undergone generational studies? How do you obliquely describe a situation that weighs, on the one hand, the possible extinction of all humanity against, on the other hand, the almost certain extinction of all humanity?
Ivy approached the house from the rear. There were still police cars parked at the front of the house, although their lights were out now. “Zoom in,” she said. Through the windows of the police cars, she could see officers sitting, sipping coffee, watching the house.
Ivy stayed low and crept to the back door. She produced a key from her utility belt and opened the back door to the kitchen. She slipped in and closed it behind her. Then she took a deep breath. Thankfully, Grandmother would be at the hospital and then spend the next few days with Great-Grandma Rose. The house should be empty.
Ivy moved through the kitchen and along the hallway past the dining room to the living room. Grandpa’s diary should be on his bedside table in the master bedroom on the other side of the living room. She stayed low so the police wouldn’t see her through the front windows. Why were they even there? The second Ivy took her pill after killing Grandfather at the hospital because her mission was complete. The dead Ivy—the one whose suit Ivy was now using—had obviously considered her mission complete after she ran her over. She’d been dead for a day and a half at least.
So which one of them had called the cops to scare her off coming to Grandmother’s house?
Ivy saw the ripple and jumped back before her brain had completely processed what she was seeing. The rippling figure jumped on her and pinned her arms.
“You’re making a terrible mistake,” Ivy blurted. “I’m not trying to save Grandfather anymore, I just want to leave a note.”
The rippled figure produced something that looked like a cattle prod. An arc of electricity burst across the two leads at the tip.
“Don’t do this. We need to talk. I’m an Ivy, just like you.”
“I...am not an Ivy,” said the man’s voice.
Okay, not another copy of her. Or, maybe he was, in a way. “Are you the oldest son of Sonny and Barb Greenbriar, by any chance?”
The ripple paused. “Deactivate cloak.” The ripple stopped rippling and revealed a figure in a dark suit just like Ivy’s. He pulled off his mask and Ivy could see that his features were similar to her own.
“Is your name something kind of like Ivy?” she asked plaintively.
“Ivan,” said the figure.
“And you were named after Charles Ives, right?”
“I was named after Ivan the Terrible,” he said.
Ivy blinked. Did that mean she was named after Ivan the Terrible? It made sense—after all, her father had been obsessed with the Russian Tsarist period. “Fudge,” she muttered. “My whole life is a lie, isn’t it?”
“Look, I don’t like this any more than you do, but the fate of humanity is at stake here.”
“I know,” said Ivy. “But you have to understand, the virus muta--aaaaaaaaugh!”
The cattle prod came down as she brought up a hand defensively and received a debilitating shock to her left arm. She instinctively kicked and sent Ivan flying a dozen feet across the room. It seemed she still had powered running turned on. She also knew that it was an advantage she wouldn’t be able to use again against him. His suit likely had the same bells and whistles as hers did, and he’d be ready for her. So instead she backed into the nearest open door and slammed it behind her, then sat against it to hold it shut. She tried to raise her hand but it didn’t work. Her left arm was completely numb and limp.
“I’m on your side,” she said. “I’ve made a mistake—we’ve both made mistakes.” Both felt like the wrong word. “All four of us have made mistakes,” she said.
“That doesn’t make any sense,” said Ivan through the door.
Ivy looked around. This was the spare room—she’d slept in it dozens of times when visiting Grandmother. She couldn’t die here. That’d be too weird. “Just hear me out,” she said. “I’m not going to try to save Grandfather. I know he made a mistake. I’m going to leave a note to myself that the cure we came up with is worse than the virus. I just need to see Grandfather’s diary.”
“That won’t be possible,” said Ivan.
“You can help me figure out what to write,” said Ivy. “ We can work on it together.”
“The diary has been destroyed,” said Ivan.
Ivy’s heart sank. “But...you can’t...”
“It’s done,” he said. “The future of humanity is at stake.”
“Yeah, I know, but it’s at stake for me too. BH-1 mutates. It will wipe out humanity without a cure.”
“The cure will also wipe out humanity.”
“I know!” said Ivy. “Yes, that’s exactly my point. We’re both fighting the wrong battles. You come back in time and defeat me, then I come back in time and defeat you, and we keep going like this forever because we both know that the other one is wrong.”
“So what do you propose we do about it?” asked Ivan.
“Suit, activate cloak,” Ivy whispered.
Insufficient power.
Ivy rolled her eyes. Typical. She called out to Ivan. “We need to leave a note for future me. If not in the diary, then in something else.”
“That’s impossible,” said Ivan. “The risk to the timeline is too great.”
“Like we haven’t been messing up the timeline already? Do you know how many more of me there are in the past right now? You’re the third one I’ve fought with since I got here.”
“It’s outside my mission parameters,” said Ivan.
“Oh, to heck with that,” said Ivy under her breath. She looked around the room. A younger version of her would sleep in this room. There had to be something here that would serve. Ivy reached up with her functioning arm and locked the door.
“Do you...do you think I can’t kick this door down?” asked Ivan.
“I think you’ll attract police attention if you do.”
“I can handle the police,” said Ivan. “I’ll be cloaked.”
“Well, I won’t,” said Ivy. “And I’ll be screaming.”
Silence from the other side of the door.
“Let’s talk this through,” said Ivy, “and when we’re done, I promise I’ll unlock the door and surrender myself.”
Ivy rose to her feet and went to the closet and opened it. She saw boxes.
“I’ve run into three of you guys, like I said. But I have to think this has been going on longer. In fact...isn’t it funny how Grandfather has had six near-fatal accidents followed by miraculous recoveries in the last year? I would bet anything that we’ve run into each other at least six times before tonight.”
Ivy scanned the boxes. Christmas ornaments. Halloween decorations. Clothes to donate to charity.
Her eyes widened. She recognized that box.
“It’s like we’re just trading punches with each other,” she said. “So, what if, instead of you and I, or other versions of you and I, or whatever, instead of fighting back and forth for control of the timeline, what if we worked together to build a stable one?”
Four shirts down in the box was a bright pink crop top with an orange sunflower on the chest. Ivy looked around and saw a magic marker on a box lid. Grandmother must have been boxing these up earlier in the day. She turned the shirt inside out—no small feat with only one good arm—and used her limp one to hold the shirt still so she could write a message in it.
Dear Ivy
“I feel like you’re stalling,” said Ivan.
“I’m not,” said Ivy, scribbling furiously.
I’m you from future
“Then why aren’t you talking?”
“I’m trying to figure out what to say. I want to help you on your mission.”
“My mission is to kill you,” said Ivan.
“Okay,” said Ivy, still writing. “That’s a teensy bit of a problem, I guess.”
Retro vaccine patient zero
Hopefully, future Ivy would figure out what that meant.
She started folding the shirt. If Ivan figured out what she had done, he’d destroy the shirt as well.
“You know what, I think we can make this work,” said Ivy. “You have a rendezvous at the warehouse after this, right? So do I. So once we get there, you can kill me yourself. The whole thing with the pill feels kind of icky to me anyway. But before we go, help me leave a note to myself so we can break this cycle.”
Ivan paused. “Fine,” he said.
Ivy stopped. Had he just agreed? “What did you say?” she asked.
“I said that’s fine,” said Ivan.
Well, criminy on a cracker , Ivy thought. She hadn’t expected him to cave so quickly. “Promise me that you’re not going to electrocute me the second I open that door.”
“I promise.”
She got the shirt folded well enough and put it back in the middle of the stack, then started fumbling with the box lid.
“Well, I guess I should open the door then? I don’t know, that felt to easy.”
“My mission was to kill you and destroy the diary. This way my mission is fulfilled.”
She put the lid back on the box and moved towards the door.
“I don’t...believe you?” she said. “But...I mean, I guess what other choice do I have?”
She reached out and unlocked the door, then twisted the handle and pulled it back. She could see Ivan standing there, just outside, waiting patiently.
He smiled, then reached out, and zapped Ivy in the chest with his cattle prod.
She stumbled to the ground. That had hurt. That had really hurt . Ivan lifted her up and hoisted her over his shoulder.
Her heart wasn’t beating. Ivy couldn’t feel her heart beating. She was going to die in a matter of minutes, if not seconds, wasn’t she?
But had it worked? Would Ivan ransack the room, or would he consider his mission complete?
“Let’s get you to the warehouse,” he said.
Ivy started to pass out, but then she felt a familiar prickling on her skin. A tide of chronal energy. It was the same sensation she’d felt when she jumped back into the past. And now it was enveloping her, and Ivan, and the room, and the entire house, and then the world beyond the house...
The timeline was changing.
On the evening of her fifty-seventh birthday, Ivy Charlene Shuul née Greenbriar had her children over for dinner. Ethan, the oldest, was setting up his tablet to show off the latest piece of software he’d been working on with his company. His wife Amber was taking a nap in the guest room with their newborn. Ivy’s other children—the teenagers—were running around outside.
“This is the bleeding edge in facial recognition,” Ethan was saying. “It de-ages your face as part of its recognition algorithm, and it does so more accurately than anything else on the market. You feed it a set of images and it tracks your entire history on the Web. Birth announcements, graduation photos, news feeds, archived cell phone footage—anything that has a picture of you in it.”
“That sounds remarkable, dear,” said Ivy. “I suppose you’re going to try it with me.”
“Oh, I’ve tested it with you multiple times,” said Ethan. “Works great. Only one outlier.”
Ivy adjusted her glasses. “So there’s an outlier, is there?”
“Nothing’s perfect,” said Ethan. “Not yet anyway. We’ve tweaked it a number of times, but it keeps feeding us the same video.”
“Can I see?” asked Ivy.
“Because it interests me.”
“I have all of this stuff working and we’re launching our open beta in two weeks and you want to see the one thing that doesn’t actually work?”
“It might really be me,” said Ivy. “You never know.”
“It’s from 2010, so it’s definitely not you. Unless you’re a time traveler or something.”
“I don’t recall ever traveling through time,” said Ivy. “Although my sister-in-law had some very promising experiments before the university—”
“Before the university lost funding. I know, Ma. But that was microbes and only a few seconds in the past and no one was able to definitively prove that the same microbes went into the past, were they? So, as much as I love Aunt Liza, it’s probably safe to say that you were never a time traveler.”
“Just shut up and show me the video,” said Ivy.
“Fine. It’s your birthday. I’ll humor you.” Ethan tapped a button and enlarged the video, which showed a woman at a zoo throwing food into a monkey cage. The woman did look amazingly like Ivy had when she was younger.
“What’s she doing?” Ivy asked.
“Feeding the monkeys.”
“I didn’t think you were supposed to feed them.”
“You aren’t,” said Ethan.
“Are those Rhesus monkeys?” asked Ivy. “Aren’t they extinct.”
“They weren’t in 2010,” said Ethan. “They had that weird STD that made their offspring sterile, but that was after this video was taken.”
“Hmmm,” said Ivy.
The video stopped as the woman was being chased off by security guards.
Ivy shivered. A feeling came over her like a wave, a succession of conflicting remembrances. She could remember a bright day in Pittsburgh and the sun on her face right before being hit by a van. She could remember fighting with an invisible woman, and then being killed by an invisible man.
She had an image of herself as a teenager stealing a shirt from her grandmother’s closet and finding a note scribbled inside. She could remember being a grad student and suddenly knowing what to do with that note.
She could remember, over and over, stepping into a chamber knowing that she was about to go on a journey from which she could never return.
She could remember that zoo, and those monkeys. She could remember tossing pellets into their cage. She could remember running from security and police, the whole time knowing she’d accomplished something that was both amazing and frightful at once, as if she were transferring a terrible fate from one side of the bars to the other. And no one would ever know.
And then, as quickly as they’d come, the flashes of images and fleeting feelings disappeared, hiding just beyond her reach.
“Ma,” said Ethan, “you okay? You’ve got kind of a thousand-yard-stare right now.”
Ivy narrowed her eyes. “Are you sure I’m not a time traveler.”
Ethan chuckled. “You may be,” he said. “After all, you’re a whole year older than you were yesterday. If that’s not time travel, I don’t know what is.”
Ivy laughed. “You remind me of your Great-Grandfather.”
“Must be why you named me after him. Now, who wants cake?”