Lono was bent over with his hands on his knees, breathing hard. He couldn’t answer at first. Eventually he lifted his head enough to push out a few words: “What … ever.” He straightened up and turned to leave. His friends followed him. Then he stopped and looked back at Rahim. “I’m gonna see you around, bruh,” he said, and moved off the court slower than he looked like he wanted to.

  Rahim went up to the skinny kid, who was talking to their teammates about the last shot. “I knew that you would make it,” the skinny kid said to a teammate. “I saw you just camping out there with a look in your eyes.”

  “I thought I had a chance,” the other kid said.

  “Chance, nothing,” the skinny kid said. “You were on a mission.” He turned to Rahim. “And you were great, too. The team doesn’t win unless the whole team plays right.”

  “Man, thanks,” Rahim said. “I thought those guys were gonna pound me.”

  “Let me be honest with you,” the skinny kid said. “I thought so, too.” His face broke out in a wide grin. “But they honored their word. You have to give them at least a little credit for that.” Rahim laughed. “Tell me, man.” The skinny kid was pointing at Rahim, and Rahim tensed up. Was he going to ask about the Spawn shirt? He didn’t. “Tell me your name,” he said.

  “Rahim,” Rahim said.

  A look passed across the skinny kid’s face. “Cool name,” he said. “I like Arabic names.” He looked like he was going to start in on an explanation, but the look faded. He held out his hand and smiled. “Nice to meet you,” he said. “I’m Barry.” Rahim shook the kid’s hand.

  Rahim expected the team to break up, that the kids would wander home, but they stayed on the court for a while and then drifted across the park to a picnic table, where they were joined by a few more kids who, from the way they acted, seemed to be Barry’s friends. One of them hauled a huge radio with enormous speakers onto a table and turned it on. A song came warbling through the air.

  “I know that song!” Rahim said excitedly.

  “You like Roy Ayers? A lot of people here haven’t heard of him,” Barry said.

  “Oh yeah,” Rahim said. “Roy.” He didn’t know Roy from Lono, but Mr. Alves had played him a song by Pete Rock and C.L. Smooth that was built on a sample from the same song that was playing on the picnic table. He thought about trying to explain that to the skinny kid: See, I know the song because a hip-hop artist in the future sampled it. Oh, what’s hip-hop? What’s sampled? And how do I know what’s going to happen in the future? He laughed to himself, but the laughter broke off quick.

  Mr. Alves! He had to get back.

  “Listen,” he said. “I gotta dip.” He held out his hand again, and Barry slapped his palm.

  “Keep ya head up, Rahim,” Barry said.

  “Bet,” Rahim said. He took off down the street and turned left at the corner.

  He’d been gone for five minutes when Barry noticed the black rock with the red streaks near the sideline.

  “Huh, that’s a cool rock,” he whispered as he picked it up and studied it.

  * * *

  Rahim ducked into a narrow space between two houses. Both had wooden fences surrounding them. He took a quick look around, didn’t see anyone, pulled out his phone, and typed in the address of Mr. Alves’s studio. It had been 4:20 p.m. when he’d left. He typed in the same return time and pressed SEND.

  A blue-green light enveloped him. As the feeling of being submerged in water overcame him, he put the phone back in his pocket. It was the only thing there.

  “Oh no,” he said. “Where’s the—” He slipped into the time stream.

  5

  “—Rock?” he finished saying as he reappeared in Mr. Alves’s bathroom. He patted his pockets frantically. “Ah, man,” he said. He’d left it behind. The whole reason for his mission and he’d left it!

  “You okay in there, Rahim?” Mr. Alves said as he lightly knocked on the door.

  “Yes,” he said. No, he thought. He couldn’t believe he’d left the rock behind, and couldn’t believe why. He was a magnet for bullies, it seemed, no matter where he was in time and space.

  Maybe I should go back and grab it, Rahim thought. He could go back, pick it up—or get another one just like it if there was any trouble—and then come back like he’d just done. But what if the trip got even more complicated than the first one? What if Lono and his pack got to him quicker? What if he twisted his ankle when he was running? What if the skinny kid’s jump shot was a little off? What if a million other things? Maybe it wasn’t really that big of a deal. Whenever he and Kasia talked to their future selves, there was endless talking about variables and temporal anomalies and all that. Kasia nodded like she understood it all. He just nodded. It couldn’t all be true, could it? Every single thing couldn’t be equally important. Maybe a stupid old rock didn’t make that much difference. In his earlier missions, he had seen some moments when time was clearly starting to rip. In Hawaii he hadn’t seen any time loops or Chrononauts or any other warning signs that the universe was going to come crashing down.

  “Yeah, I’m okay, Mr. Alves. I’ll be right out,” he said. He washed the dirt from his hands, splashed some cool water on his face, and left the bathroom.

  * * *

  After finishing his music lesson and coming home, the first thing Rahim did was call Kasia. It was part of his post-mission protocol. The whole time he had been back in 1978, in Hawaii, she had been in a protective bubble. He didn’t understand the science behind it. He didn’t understand the science behind any of it, despite how many times both Kasia and her future self tried to explain it to him. But because she had a connection to the phone through her computers, she was immune from any changes he might have caused, at least for a little while. So was he. It was like the two of them were breathing through a tube across time, and there was no chance that they could drown.

  He didn’t understand the science, but as Kasia said, he understood the applied science. What she meant was that he had gotten better at time traveling since they’d first stumbled upon it last year. That was an adventure he couldn’t have imagined before it happened, meeting Dr. Jackson and the Men in Gray, the government agents who worked with her.

  Kasia and Dr. Jackson had gotten pretty close since last winter. Partly because of the Men in Gray. The agents had tracked down Kasia through her hacking of their satellites that had initially powered the phone she had created. Rahim was sure that they were going to arrest her for it, and that would be the last he would see of her unless he visited her in federal prison. Instead, the Men in Gray had gone the other way. They had realized that they had met the only kid in the world who could have done what Kasia had done, and they had offered her an internship in Dr. Jackson’s lab downtown. Rahim had been invited to go, once by Kasia, once by Dr. Jackson herself, and he had even nodded like he was thinking about it, but the truth was that he got a headache just trying to work out all the math Kasia and Dr. Jackson were probably doing in the lab. Kasia’s time in the lab not only challenged her, it made her happy. She was meeting people, talking to them, learning to work with them, and she realized that she was pretty good at it. Rahim thought that might have influenced her decision to stop being homeschooled and actually go to class with him.

  And that was a good thing. Wasn’t it? He shook his head. Stop it, he thought. Of course it’s a good thing. Kasia is happier. But was he happier? Rahim was starting to feel like an afterthought. Kasia needed people who spoke her language, who were on her level. He was still her best friend, but he knew she noticed that his eyes glazed over when she started talking that really complicated science stuff. She was happy, and he was happy for her, but he wasn’t sure about the rest of it.

  Rahim dialed Kasia’s number. She answered through her computer.

  “So, everything good?” Rahim asked.

  “I think so. Let me just check the past five years…” He heard keys clicking. She had explained to him that she looked through a bunch of databases and search engines, comparing what she was finding to the historical record that she had saved before he went back in time.

  The clicking went on, and on, and on some more. Finally Rahim couldn’t stand it anymore. “Well?” he said.

  “Hang on,” Kasia said. “It’s not a difficult process, but I still have to make sure that I get to all the…” She paused. “Uh-oh.”

  “Uh-oh, what?” said Rahim. “Uh-oh is never good.”

  Kasia let out a sigh. “Everything was looking okay. I checked the natural disasters, like hurricanes and earthquakes. They were the same. I checked the sports championships. They were the same. I was feeling pretty good about it.”

  “But then you said ‘uh-oh.’”

  “Well, as I was finishing up, I looked at the tab for our school. I had it open because I was checking the schedule for the talent show auditions.”

  “That talent show was canceled? Oh no. I ruined everything.”

  Rahim was joking, but Kasia didn’t laugh. “No,” she said. “It says here that the National Teacher of the Year will be coming to our school next week for a special visit.”

  “Uh … okay?”

  “It’s not okay. Do you know who the Teacher of the Year is?” She paused. “I’ll give you a hint. He’s from Hawaii.”

  “I have no idea,” Rahim said.

  “I think you might.” She read from the school web page. “Mr. Obama, renowned for his exciting and innovative teaching techniques, wants kids to not only get interested in geology and Earth sciences, but to get deep into learning of all types.”

  Rahim’s head was spinning. “Wait,” he said. “What? The Teacher of the Year has the same last name as President Obama.”

  Kasia answered with a different tone, the tone she used when she saw everything and was talking to someone who only saw a little piece of everything. “Rahim,” she said. “What did you do?”

  Rahim was catching up to Kasia, but that meant going back to his mission. “I got the rock,” he said. “I had it in my hand. But then these bullies wanted the phone and started chasing me. I had to run away from the monument down into a neighborhood to escape them. When I got there, these other kids ended up protecting me from the bullies. Well, one kid mainly. This tall skinny kid named Barry.” The rest of the truth fell on him like a boulder. “Oh,” he said. “Oh no.”

  “I think you mean ‘uh-oh,’” Kasia said.

  “You think the kid who helped me was President Obama?”

  “I think the kid who helped you never ended up becoming President Obama.” Barry was Barack? Rahim remembered the way Barry had reacted to his name. “Cool name,” he had said. “I like Arabic names.” He liked them because he had one.

  “The problem wasn’t him helping you,” Kasia said. “That alone would have kept him on his leadership track. The problem was the rock.”

  “I left it on the basketball court by accident. When I came back to Mr. Alves’s place, I thought about going back and getting it. But how much was a rock going to matter to me, anyway?”

  “It’s not about how much it mattered to you,” Kasia said. She kept reading. “‘Mr. Obama frequently tells the story of how he was a somewhat indifferent student, more interested in pickup basketball, until he found a volcanic rock and began to think about the Earth’s amazing history.’”

  Rahim was flat on his back now, on his bed. He turned his head to look at his trumpet case. It looked the same. He turned the other way to look at the posters of Four the Hard Way and the Roots on the other wall. They looked the same. But nothing was the same.

  Kasia was typing again. The clacking should have made him more nervous, but it made him calmer. Maybe she could figure things out. “Listen,” she said. “I have to figure out if anything else has changed. And when I figure it out, you know that we have to tell our future selves, right?”

  “We do?” Rahim hated the idea of seeing them on the screen, their disapproval flowing back through the years.

  “Of course,” she said. “They have a wider view, so they can take a better measure of what ends up happening down the line, make sure no time vortexes or time loops are happening. Last thing we need is dodo birds running down Market Street again.”

  Rahim made a sound halfway between a grunt and a groan. He should have zipped back out of Mr. Alves’s bathroom, gone back to Hawaii, gotten the rock, and then there would have been no Teacher of the Year coming to the middle school who had the same name as the president. Or no: who was the president. Or no: had never been president. For that matter, he shouldn’t have dropped the rock in the first place. But as his mother always said, no sense crying over spilled milk. And as Kasia always said, there was all the time in the world. He flopped flat onto his bed, face down in the mattress. Just when he thought he was getting good at this, something happened to show him he didn’t really know what he was doing at all.

  “Okay,” Rahim said. “We can talk to them together. I’ll be over there in a little while.”

  “Okay, come on up. My mom is making bok choy soup again. You’ve been warned,” Kasia said. Her parents were dedicated vegetarians who ran a vegetarian co-op grocery store. They also were urban farmers who helped maintain several gardening spaces around the city. They grew most of their own produce, like bok choy, which Rahim was not a fan of at all. Still, he ate the soup Kasia’s mom made once out of respect. It was the least he could do for his best friend, though sometimes it seemed like the most he could do. The taste was impossible to tolerate. He’d rather eat wet sandpaper.

  He tried to get up to Kasia’s room without getting stuck in the kitchen. But her mom and dad were there, and they were happy to see him.

  “You want some eggplant, jackfruit, and artichoke soup, Rahim? We have bok choy soup, too, but that isn’t done yet,” Kasia’s mother said.

  “Uh, no thank you, ma’am,” Rahim said as he headed up the stairs. Bok choy was one bad ingredient, which was bad enough. How would three bad ingredients all mixed together taste? He wasn’t even sure what jackfruit was, but he was almost sure he wouldn’t like it.

  Kasia was sitting at her desk with Iago perched on the edge. Iago was the robotic drone that she had built a few years ago on an afternoon when she was bored. He was semi-autonomous, which meant he could do some things on his own, but mostly he did what Kasia told him to do.

  Mostly.

  “Okay. Let’s call them,” Kasia said.

  Rahim sat on Kasia’s bed and watched her plug the phone into her desktop computer. The screen came alive with a multitude of colors, then went black. After a few moments, their future selves were on the screen.

  “So, you met Barack Obama,” Rahim’s future self said.

  “He helped me,” Rahim said.

  “But helping you didn’t help things, if you know what I mean.”

  “It changed him being president,” Rahim said.

  Future Rahim nodded slowly.

  “Did it change more than that?” Kasia said.

  Rahim’s future self looked at Kasia’s future self. “Yes,” he said. “You could say that.”

  “Where are you?” Kasia said. For the first time Rahim noticed that their future selves were not in their usual location. There were no computer screens behind them. They were in what appeared to be a dark cellar or basement, papers hanging on the walls, string connecting the papers.

  “That’s not important. Let’s talk about the mission. We tasked you with one thing, which was to obtain the rock and return. The failure of that mission was far-reaching. It goes well beyond Barack Obama’s presidency.”

  “How so?” Rahim asked. His stomach felt queasy, like when he drank too much chocolate milk.

  “Again, don’t concern yourself with that,” Future Kasia said. “Focus on fixing the situation. Go back and make things right.” Her voice was going up in volume, and her eyes were widening. Future Rahim touched her arm. She took off her glasses, rubbed her eyes, and put them back on.

  “I have some questions about—” Kasia said.

  “Please,” Rahim’s future self said. “No questions. We need to address this quickly. We are in danger. The Aevum Organization is in danger. The whole world is in danger.”

  Kasia was still looking curious, like she was going to ask more questions, but Rahim wanted to get on with it. “Okay,” he said. “So I go back and get the rock?”

  “What?” his future self asked.

  “The rock. The one you said I had to go get in the first place. The one l left behind. If I go and get it, that will fix everything, right?”

  Their future selves shared a glance. “The rock is part of it, yes. But things have changed.”

  “Right. I’m trying to un-change them.”

  “Yes,” Future Rahim said.

  “Un-change them,” Future Kasia said.

  Neither of them sounded convinced. Rahim knew he wasn’t the smartest kid in his class. Heck, he wasn’t the smartest kid in the room. But he could tell that whatever had happened had scared their future selves. They were acting weird.

  “Sometimes,” Future Kasia said, “ruptures in the time stream are harder to handle. If the same person returns to repair them, time sees it as too similar to what has already occurred and defaults to the same circumstances.”

  “Meaning what?” Rahim said.

  “Meaning,” Kasia said, “that I should go along this time.”

  Future Rahim objected. “But, Kasia, you’re his anchor to the present.”

  But Future Kasia held up her hand. “I think it’s not a bad idea.”

  “Of course you think that,” Future Rahim said. “The past version of you is the one who had it.”

  “But look at what we know about time,” Future Kasia said. “Maybe two people need to arrive at that site to reset events.”