“Don't worry!” shouted Naomi, her voice hoarse in the smoke. “It'll be OK!”

She was shouting over the roar of wind and flame, but she didn't need to bother, not really. Even now, perched twenty-one stories up, with everything that had happened today, Mara knew what Naomi was thinking. After all, 'Don't worry' and 'It'll be OK' had always been Naomi's mottos – the statements she lived her life by.

Of course, Naomi was usually right about both statements.

A long time ago, they were in high school, Mara had picked up some history book. Not really a history book, it was one of those ones that sprinkled history and politics with opinion, kneaded everything into something that looked coherent at a glance, and then half-baked into philosophy. It was a light and easy read, even if the book was to real history texts what Harlequin Romance was to Shakespearean tragedy. Mara finished it anyways. There was one concept threaded through the book that stuck with her.

The world was made up of blondes and brunettes. Blonds were probably what Kipling called a son of Mary. People with a sunny and optimistic outlook, an outlook reinforced by chance as good thing after good thing happened to them. In the book, the United States was a blonde nation. Founded as a city on the hill, following manifest destiny, and then gifted with a continent already (mostly) depopulated, filled with natural resources; and right when the new continent was filling up a world conflict broke out that ended up transferring all of Europe's wealth to New York City. Blondes.

Like Naomi. The popular girl, gifted with natural athletics and a bright smile. The girl who could trip and fall and always get helped up by the cutest boy in the hallway. The girl who could show up on the first day and get assigned to be lab partners with the shy genius. That girl, the blonde.

Brunettes, on the other hand, were the sons of Martha. Pessimistic, and rightfully so, since they had to work for everything they got. Sweat and blood pouring into every accomplishment. But no matter how hard they work, they still have to watch the damn blondes swanning their way to the top with a smile and a wave.

Mara was a brunette. She always had to stand back up on her own. She studied for hours for her grades. And if she showed up late she’d just have to do the project on her own. Because she was a brunette.

Mara believed this theory all the way down into her soul. After all, she had a perfect example right in front of her, even if Naomi wasn't blonde. Naomi's thick and perfectly straight hair was raven black – the kind of black that looks blue in the sunlight. Mara herself was actually blonde, which just made her feel even more bitter about how they had to go through life. Mara wasn't even the sort of blonde that you can be proud of, just the dirty light brown with paler highlights from the sun that people call blonde to humor an insecure girl. Mara made sure her driver's license said she was brunette.

What made Mara even more unhappy was that she had never been able to dislike Naomi. Naomi never did anything that Mara could actually be angry about, and so whenever Mara did feel jealous she got to feel guilty too.

Mara and Naomi were twins.

Fraternal twins, of course. They both had the same opportunities through childhood – the same home, the same parents, the same toys, and the same outings. But somehow, it was always Naomi's bright smile in the lead, with Mara quietly following. It was Naomi who became a cheerleader, and a star player in their school's lacrosse team. Mara just read a lot. Naomi was student body president their senior year, while Mara helped with posters and prom decorations.

Once in a while, Mara wished that Naomi could at least be a ditz. Why couldn’t Naomi be a socialite who didn't bother with anything serious? But Naomi took all the same advanced classes that Mara did and got the same high scores. It never seemed fair, Mara studied constantly, but Naomi split her efforts between all sorts of activities and still did well.

If they had stayed on the same track through college, Mara may have learned to despise her sister. But they went to different schools. Naomi went to Kent State and took mechanical engineering classes. Mara stayed near home, but only because Carnegie Mellon was close. She studied physics. She was good at it too; math and science held an elegance and symmetry that other disciplines lacked. She had taken enough advanced classes that she was even able to graduate in three years.

That was why they were both back at home, to celebrate Mara's graduation, and to celebrate that she had gotten a great job offer as a research assistant along with a scholarship to work on her graduate degree. It was just Mara and Naomi for the weekend. They had planned on maybe eating out, going dancing, or maybe just hanging out together at home and watching old movies. Instead, here they were, standing outside the last staircase down from their parents’ apartment.

“It'll be OK, they design these things for fires and stuff. The doors shut automatically,” Naomi was saying.

“Then why were the other four stairwells just big chimneys?” demanded Mara. She was a little out of breath, she regretted cutting most of her cardio out of her routine the last couple of years. But Naomi was out of breath too, so who knows.

Mara held the back of her hand to the big steel doors. Amazingly, they were cold. Well, they weren't blistering hot like the others. Naomi had scorched her eyebrows to a blast of flame after throwing open the first set of stair doors. And, damnit, somehow the soot on her face still framed everything in a way that made the girl's big eyes look sharp and confident. Mara was sure that if she lost her eyebrows she'd just look unfinished or doughy or something.

They carefully opened the fire doors, and while not getting blasted by gouts of flame was nice, there was still smoke that trickled out.

“Now what?” said Mara. She had tried, really she did. But even at twenty-two she didn't manage to keep the whine of her fear out of her voice. “We can't get down. Even if the fire isn't there, there's no way we can get down nineteen stories in the smoke.”

Naomi paused for a moment, then smiled, “No problem, we weren't going down anyway. Not to that.” Her eyes darted to a window for a moment then back at her sister. “Remember? Daddy was already sending a helicopter to get us and everyone. It should be here soon, so we're going up, not down. It's only two floors, we can hold our breath and climb that.”

Mara couldn't bring herself to speak. She just looked back down the hallway, wishing they could just hide in the apartment. She nodded, and the two of them took deep breaths and plunged into the smoky stairwell. Naomi was right, she was able to get to the roof access without taking a breath. Except the door was locked.

Mara pounded on the door a few times, then broke down and took a deep breath. Predictably, she just started coughing and fell to the ground. Naomi, instead of just hitting the door, threw her shoulder into it. She must have remembered a few things from her lacrosse days because the door banged open on the first hit. Mara scrambled outside and took a few breaths of the cleaner air, then noticed that Naomi had fallen to the ground by the door.

Naomi's eyes were closed and her mouth was screwed up tight. Mara’s whole body flinched when she realized that Naomi's shoulder was deformed, the arm held tight to her body but still just wrong. Mara helped Naomi up as best she could, and they moved farther from the doors onto the roof. There was a bunch of people there, Mara hadn't realized that there were so many people still in their building. Most of them had left the night before when the riots had started.

The girls had chosen a three-day weekend for their celebration, but labor day was a popular day for protests. Elijah and his Righteous Knights were the big one in Pittsburgh that weekend. Mara had heard of his group before. She didn't think they were terribly unusual or radical – not like the supremacists or anti-distributionists she had learned about from her parent's generation. The Knights mostly wanted jobs, reasons to get dressed during the day. It seemed reasonable to Mara – she was going to be a researcher, and she didn't think she'd be happy without something like that in her life to drive her. Just hanging out at home and getting handouts seemed like Hell to her.

Naomi and Mara had turned on the news when they started hearing cheers and shouts through the window. The crowds had been big enough that they didn't want to go out.

“They're angry today,” Naomi had said. “They're right, but wow. I wouldn't want to be a CEO or politician in front of that crowd.”

“Yeah,” answered Mara. “I'm glad daddy is in Harrisburg.”

They watched as Elijah gave his speech, as the crowd shouted themselves horse, chanting slogans and just venting anger into the air. The noise redoubled when the police showed up. Mara recognized the old-fashioned crest of the state police on the big vans. She hadn't seen what they were wearing before though.

“Is that the new stuff, the plastic metal I've been hearing about?” asked Naomi.

“Yeah, you're right, it's Plasma Steel,” she said. She should have recognized it; the white and shiny armor had been in the news for a couple of years since the army had begun issuing it. Her lab at Carnegie even had a bunch of plasteel tools and equipment. She hadn't realized that Pennsylvania had bought some for their police.

The police demanded that Elijah surrender himself, and they named a few others. They ordered the crowd to disperse. Then someone threw something at the police. Mara wasn't sure, but on the TV it had looked like a plastic water bottle. The cops opened fire, and the news cut out. Even without the TV, the girls could hear the gunfire go on through their windows. It stopped after just a few minutes, but by sundown, they were hearing shots coming from all over and could see smoke rising from over the skyline.

Things were still crazy the next day. Worse, if anything. The fire alarms started in their building that afternoon, prompting the girls to leave their apartment. They hadn’t been able to get through to 911, but their father had answered and promised to send help.

A couple of the men in the group on the roof spotted Mara pulling Naomi out of the smoke and ran over to help the sisters. Mara waved them off, “Careful, she broke her arm I think.”

The older of the two men looked at it, and said, “Nah, it just looks dislocated. It'll hurt like hell, but as soon as you get it popped back in it should feel better.”

“Can you do it?” asked Naomi through gritted teeth.

“I'd probably just make it worse,” he said. “I've seen it happen a few times, but I'm not a doctor.”

“Is there a doctor here?” said Mara. When the man shook his head, she asked, “Now what?”

“I don't know, we wait and hope the fire doesn't climb, I guess,” said an older man. “I thought those stairwells were supposed to be able to stay clear in a fire.”

“Who knows,” said another sooty face. “It's an old building, maybe the stairs aren't really fire escapes. Maybe the rioters blocked them on purpose. Maybe the cops thought that anyone left were sympathizers. Doesn't matter, does it?”

Mara recognized Mrs. Shipley. Mrs. Shipley lived upstairs and chaired the co-op board. The girls' dad always referred to the woman as 'that old battleship.' Mara could never tell if he was joking or not when he said it. She wasn't in her normal pantsuit though, she was dressed in sweatpants and a button-up men's shirt. And she was talking quietly into an old-fashioned cell phone.

She snapped it shut with a flourish, and said, “Enough. We'll be fine. Apparently Senator Brown already arranged a copter to pick up his girls. I gave them a count and SAR is sending a second one. They should be here within an hour. Sit quiet, and stay away from the edge.”

It sounded like good advice, and everyone was tired, so everyone just found a place to sit. Mara watched her sister, and couldn't help but think of the time she had broken her own arm. They had been eighteen, seniors, and had managed to get their prom dates to take them dirt biking the day before the dance.

Naomi had already been zooming around the patch of woods while Mara's date was showing her how to handle her bike. Of course, the moment Mara had started it, the bike had roared and took off. When the front wheel lifted off, she lost control and tipped the bike over an embankment. She was lucky not to get trapped under it but had obviously broken her arm.

Naomi had seen it happen and zipped the bike over. Taking charge, she had yelled at Mara's date – the boy had been just standing there and laughing at Mara – and gotten her own date to call 911. She had ridden with her sister in the ambulance and stayed by her bed while the doctors checked her out. No concussion, even though none of the kids had bothered with helmets. Just scrapes and bruises and a complete transverse fracture through both her radius and ulna.

“Just go,” Mara had said the next day from her bed.

“Nope, I'm going to watch Gone with the Wind with you, couldn't miss it,” said Naomi.

“You've been excited about tonight for months, go,” repeated Mara.

“Nothing to be excited about, really,” explained Naomi. “I thought it would be fun to do the double-twin-double-date thing. But Taylor's boring and Nick is a dick.”

“He didn't realize I'd been hurt so bad,” said Mara. She wasn't quite so strident now. Either she was giving in or the painkillers were taking effect.

“Doesn't matter,” said Naomi. “Boys who laugh at girls who fall down are dicks. So Nick is a dick. And more importantly, I'm going to stay home and watch a movie with you.”

Mara changed tack, “But your dress, you don't get to wear stuff like that so often...”

“Because I'm a kid,” said Naomi. “I'll have lots more chances. Just watch, the weddings will start soon! And the dress isn’t that poofy, I can wear it then. Or maybe I'll wear it to the Mud Run this July. That could be fun too. Imagine! I'll be splashing my way over five kilometers wearing a silver-sequinned dress with an open back and thigh-high slit. I'll bet I can even find a sports bra to match it.”

Mara couldn't help herself, she had laughed at the image. And she had laughed harder when Naomi had worn the fancy ball gown for the race. The thought made her laugh again, despite still hearing shouts, screams, shots, and explosions from the city below.

“What?” asked her sister.

“Oh, I was just thinking about your race, remember? The one where you wore the dress?” said Mara.

“Ha. Yeah. We should have grabbed something fancy from our closet before coming up. Would have made a way better picture,” said Naomi. “Or better, I should have Mess dress uniform, I packed it with me, just in case.”

Mara was going to be a researcher, and help unlock and apply all the new discoveries that had been upending things. Naomi was going to be a pilot. While Mara had been on her accelerated graduation course, Naomi had signed up with the Air Force. They were putting her through school, and she was going to start a flight program the next year.

They sat, quietly, on the roof. Mara was pretty sure that everyone was listening carefully to the roar and crackle of the flames. She didn't think the fire was climbing much, it's hard to burn down a steel and brick building, but Mara couldn't put it out of her mind. She was sure no one else could either But after a little while, they could hear rotor blades through the noise of the fire and fighting. One chopper landed on the roof, its rotors still pushing air hard. A man in a red jumpsuit and white helmet hopped out, and shouted at them, “Come one, we can take fifteen people – quickly please!”

Naomi tried to get Mara to board with her. Mara looked around, Naomi was really the only one hurt, beyond a few that were coughing and one middle-aged guy who had burnt his hand on something. Mara didn't recognize everyone, but there was Mr. and Mrs. Rohani – they had two kids away at summer camp. And Charlie Eldritch, he was the building's super and had always been nice to Mara and Naomi, even when they had forgotten their keys for the thousandth time. Ron Goldenberg used to help her with math back in junior high, while his wife made her cookies. The cookies had always been dry, hard, and kind of tasteless, but Mara had loved it anyways.

She just couldn't fly away with everyone else behind. So she got Naomi buckled in, wincing at the tears on her sister's face as she tightened the harness over her shoulder. Then she hopped out and grabbed Mr. Kline. Mr. Kline was a widower and had been living alone in the building for as long as Mara could remember. Whenever she had gotten cookies from Mrs. Goldenberg, she had taken them to Mr. Kline and talked with him for a little while. He would tell her stories about his kids and grandkids, but his best stories were the ones about the people he had worked with when he had been an architect. She grabbed Mr. Kline and pushed him onto the helicopter.

Naomi had called out, wanting Mara on board with her, but Mara just smiled and said, "Don't worry, it'll be ok!"

The jumpsuited man glanced over everyone, making sure they were strapped in, and they took off. The second helicopter landed moments later, and Mara waited until it was just her and Mrs. Shipley. They smiled at each other, grimly, and got on board.

The helicopter lifted off and began to follow the first east out of the city. But there was a sudden jerk followed by silence, and the whole craft began to spin, slowly. She could see the two pilots up front frantically managing levers and buttons as the whole copter drifted down out of the sky. Somehow, they managed to land on the bank of the Monongahela. The crash jarred Mara, but other than shocking her a bit, she wasn't really hurt.

As Mara’s hearing came back, she heard one of the pilots into his headset, “Don't, keep going, we're fine!” Mara looked up and saw the first helicopter circling back around to check on them.

“I don't know where it came from, just keep...” the pilot was interrupted by a thump from a few blocks over.

Mara watched, horrified, as a sudden trail of smoke impacted her sister's helicopter in a burst of flame. This time she could recognize the explosion the helicopter crashed into the side of a building.

Decades later, Mara smiled, placing her hand on the little craft they had built. It was basically a big aerodynamic box set between two drives. Mr. Holden still insisted on calling them Plasma Drives, but her assistant Joey had started calling them 'nacelles,' ever since they had realized the drives needed to be paired to be stable. Joey called the craft a shuttle, too. Mr. Holden was going to hate that, but that just made her more inclined to use the same terms.

It never did end up mattering how hard she worked, she still failed a lot. She couldn't protect people, she screwed up, and she always felt jealous about how easy it came to all the blondes around her. But she couldn't stop working, either. This time, though, the shuttle was going to fly. It had passed its tests, and all that was really left was to show it off. If anyone got to name it, she would.

Dr. Hansen didn’t really care about the terms, but he’d wanted something a bit more noteworthy for the craft’s actual name. Mara had put her foot down on that too. The shuttle was her project.

“Naomi” was stenciled clearly on the sides.