"Hiro!"

More laughter, but finally the elevator door slid open, and she and Moggle slipped inside.

Hiro and Ren were still laughing when the door opened again. The two were splayed across the couch, playing a thumb-twitch game on Hiro's giant wallscreen. Explosions and the chatter of gunfire were making the strings of paper cranes rattle and dance.

"What are you two doing?" Aya shouted over the noise.

"The Nameless One just kicked some story slamming thumb-twitch games," Ren yelled. "So we've devoted ourselves to a day of war!"

She rolled her eyes. Hiro was still annoyed at the Nameless One for slamming the crumblies in his immortality story calling them freaks and world-wreckers. "Isn't it kind of loud, though?"

"Sorry, Slime-sensei," Hiro yelled. "Nice work on your face rank, by the way. A few more appearances as Slime Queen, and you'll get an invitation to the Thousand Faces Party!"

She scowled. "Aren't you the one who always says there's no bad fame?"

"No, that's the city interface," Hiro cried. "I'm against slime-fame!"

Ren giggled, falling to one side to coax his thumb-twitch character through some perilous maneuver.

"What are you laughing at, Ren?" Aya shouted. "You're the one who made me go underwater!"

"I didn't know you were going to talk to some big-face pretty boy on the way home."

"Neither did I!" Aya screamed over the explosions.

"Sure you didn't," Hiro answered. "Just like when we saw Frizz Mizuno's feed yesterday, and you had no idea who he was."

"I didn't know him yesterday. I didn't know his name, anyway. I'd just met him the night before

... at this party."

Hiro frowned, then made a gesture. The wallscreen images froze, the sound abruptly shutting off.

"Since when do you get invited to the same parties as Frizz Mizuno?"

"I wasn't exactly invited," Aya said. One of Hiro's eyebrows rose, and she groaned. "I crashed this tech-head bash, okay? I was looking for the Sly Girls."

"Oh, the imaginary Sly Girls again." Hiro let out a long sigh. "Why are you wasting your time with unicorns, Aya-chan?"

"They're not imaginary. Actually, I joined up with them last night."

"You joined the unicorns?" Hiro asked.

"The Sly Girls, you bubblehead. I even went surfing with them."

"What do you mean?" Ren asked.

"You guys haven't heard of mag-lev surfing?" Aya gestured, and Moggle started loading a stack of shots into Hiro's wallscreen. "Then you need to watch this."

Hiro started to say something, but the wallscreen was already flickering to life. He crossed his arms, staring in silence as Aya's night as a Sly Girl began to unfold.

When it was over, the first thing Hiro said was, "Mom and Dad will kill you."

Aya couldn't argue. Her parents didn't even approve of bungee jumping. She couldn't imagine what Mom was going to say after watching her mag-lev surf.

"Crumblies are the least of your worries," Ren said. "After you kick this, the wardens are going to visit."

"I know." Aya sighed. "That's the bad part about kicking this story. Nobody's ever going to mag-lev surf again."

"That's not what I mean," Ren said softly. "The wardens will forget all about surfing once they spot that mass driver."

Aya glanced at Hiro, but he looked as puzzled as she was.

"What's a mass driver?" she asked.

Ren stood and crossed to the wallscreen, rewinding the images with a twirl of his finger. He froze the shot where Moggle was climbing up the shaft, reached out, and pointed at the glint of metal embedded in the stone. "That's a copper coil, right?"

"I guess," Aya said. "Like in an electric motor?"

"Or a train track," Ren said. "Mag-levs have two kinds of magnets. The ones that levitate the train and the mass drivers."

"Which do what?" Aya asked.

"They move the train. As it glides along, the mass drivers switch from negative to positive - pulling from in front, pushing from behind, sending it faster and faster. You can do the same thing straight up."

"So this shaft is like a mag-lev train that goes up and down?" Aya shrugged. "You mean it is an elevator?"

Ren shook his head. "This could accelerate a thousand times faster than any elevator. You saw that airlock, right? If you suck all the air out of the shaft, you're accelerating through a vacuum. No friction at all - pure speed. With enough juice, a mass driver could throw you into orbit."

"But what's the point?" Hiro asked. "Why hide it in a mountain?"

Ren stared at the image of the copper coil. "That depends on what those cylinders are."

Aya shrugged. "They just looked like big hunks of metal."

"What if there's smart matter inside? They could change shape as they fly, make fins and wings to guide themselves to a target. Maybe even whip up a heat shield as they fall."

"No way, Ren." Hiro sat up straight. "The Nameless One is actually right - our thumb-twitch games have made you war-crazy!"

"Very funny, Hiro." Ren moved the image to a close-up of a cylinder. "Let me do some math.

How big are they, Aya?"

"Um...maybe a meter across the top? And a little taller than me." Aya frowned. "What are you getting so excited about?"

"He's delusional," Hiro said.

"Let's say two meters tall." Ren's fingers twitched and spun, and numbers began cascading across the wallscreen image of the cylinder. "So the radius squared is a quarter of a meter, times pi is about point seven-five. Times two meters tall is one and a half. Hey, room? How much would one-and-a-half cubic meters of steel weigh?"

"What kind of steel?" the room asked.

"I don't care. Just round it off."

"Almost twelve tons."

"Twelve tons!" Ren took a step backward and fell into Hire's feed-watching chair, staring wide-eyed at the screen.

"What's the big deal?" Aya asked softly.

Hiro leaned forward, the amused expression fading from his face. "Hey, room? How much energy would twelve tons of steel have if you dropped it from orbit?"

"From how high in orbit?" the room asked.

Hiro glanced at Ren, who shrugged and said, "Two hundred kilometers? Forget about air resistance and round it off."

The room hardly paused. "The object would land at two thousand meters per second, releasing twenty-four gigajoules, equal to six tons of TNT."

"Okay...that's not good," Hiro said.

"What's TNT?" Aya asked.

"These days, it's a unit of energy," Ren said. "But a long time ago, it was a chemical that Rusties used to make bombs."

"Bombs?" She swallowed. "Like when they used to shoot missiles at each other?"

"Wow, Slime Queen," Hiro said. "You catch on quick."

Ren nodded slowly. "This could be some kind of city killer."

"You're not serious." Aya remembered the Rusty weapons that had destroyed whole cities in seconds, burning the sky and leaving the ground poisoned for decades. "But city killers had warheads.

Those cylinders are just solid steel!"

"Yeah, Aya, and the dinosaurs were wiped out by iron," Ren said. "Iron falling from space.

These things wouldn't come down randomly. The smart matter could split them into slivers, one for every building in a city. How many of those cylinders did you say there were?"

"There were hundreds, Ren," she said softly.

"Thousands of tons?" he said. "With the metal shortage going on?"

Aya shook her head. "But aren't you guys jumping to conclusions? We don't even know if there's any smart matter inside."

"Maybe I can get you something to test them," Ren said.

"Would a matter hacker work?" Aya asked, and they both turned to stare at her. "Because the Sly Girls sort of, um...have one."

"Aya," Hiro said slowly. "Don't tell me you've been playing around with matter hackers."

"I never even touched it!"

"Aya! Matter hackers aren't just merit-losing illegal; they're going-to-jail illegal!"

"It's perfect, though," Ren said. "Just send a basic run command to one, and watch what it does."

"Ren!" Hiro shouted. "No way is my little sister spending another second with those Sly Girls. Do you want my mom and dad to kill me?"

Ren turned to her. "If you don't want to go, Aya, I'll try to get in there. But it's your story. ..."

Aya didn't answer at first, staring at the tangle of math on the screen, remembering when she was ten years old. Her entire littlie class had been loaded into hovercars and taken to an ancient ruin from the Rusty's second global war. A burned-out shell of a dome rose up from shattered walls with empty windows, marking where a hundred thousand people had died in one quick flash. She hadn't believed it possible, not even of the Rusties.

But it looked like someone was following in their footsteps.

"Sorry, Hiro, but I have to," she said. "The end of the world isn't something we can kick halfway."

Part II

CITY KILLERS

Lurking behind every chance to be made whole by fame

is the axman of further dismemberment.

- Leo Braudy The Frenzy of Renown

BANNED

The Sly Girls were not pleased with Slime Queen.

It turned out that Kai watched the others' face ranks as closely as her own. Aya's sudden jump from obscurity to mild fame hadn't escaped her notice. After several pings back and forth, Kai admitted that maybe it wasn't entirely Aya's fault, but it was still a problem.

No hovercam-magnets allowed.

So Aya was banned from the Sly Girls, at least until her face rank fell back into six figures.

At first Aya thought the delay would drive her crazy. Here she was, a huge story finally in her grasp, and she had to wait for a bunch of nobodies to stop making fun of her about nothing.

On top of that, Aya didn't dare hang out with Frizz until this was all over. If anyone spotted them together, another wave of Slime Queen slamming would erupt, driving her face rank back up.

But as the days passed, waiting turned out not to be so bad.

Aya stayed in her room, avoiding classes by claiming that her underground lake chill had worn her out. She took all her old stories down from her feed for a week, and only answered pings from Hiro, Ren, and Kai. And gradually Aya Fuse (and her alter ego, Slime Queen) began to disappear, her face rank dropping thousands every day.

The strangest part was not having a feed. For the last two years, everything important to Aya had been stored there: images, stories, class schedules, and grades. Lists of everything she did and thought and wanted, and of all her friends and enemies. Even if hardly anyone ever looked at it, blanking her own feed was like erasing part of herself.

Fortunately Aya had plenty to keep her occupied.

It took a whole week to edit a rough draft, making sure to conceal the awful truth until the end, yet still revealing enough to keep people watching. It was the longest story she'd ever kicked - almost twenty whole minutes. Hiro told her to shorten every version he saw, but Aya wasn't worried about anyone getting bored.

The story had everything: eccentric outsiders, mysterious technology, eye-kicking shots of the wild, even a near miss with a mag-lev train. And of course, good old humanity trying to wreck the planet once again - all the promise and danger of the mind-rain wrapped up in one big kick.

The only thing she left out was the trio of inhuman figures she and Miki had seen. There weren't any shots of them, after all. And surely city-killing weapons were enough, without adding implausible aliens to the mix. She didn't even mention them to Hiro and Ren, who would probably just say she was believing in unicorns again.