"Out here with the Sly Girls, I get to keep something for myself."

Aya heard a burst of laughter - the other Sly Girls were gliding toward them down the tracks.

She only had time for one more question.

"So if you don't care about face rank, why did you break up with your boyfriend?"

"Who says I broke up with him?"

"A hundred or so feeds, last time I looked."

"Don't always believe the feeds, Aya. He's the one who couldn't stand people talking about our

'difference in ambition.' So the little moron ran away."

Eden floated a few centimeters lower, reaching out one finger till it was almost touching Aya's nose.

"And that, my Nosey-chan, is what being an extra really means."

THE MOUNTAIN

As they approached the tunnel mouth, a few of the Sly Girls pulled out flashlights. Beams of red played across the opening, barely piercing the darkness within.

At least Aya wasn't the only one without infrared.

"What happens if a train comes while we're in there?" Pana asked.

Kai shrugged. "Just lie flat on your board, up by the ceiling."

Eden shook her head. "That won't work. The train's wake would pull you down." She hooked her thumb at Aya. "Sort of like what happened to Nosey-chan here."

A few of them laughed. On the way back to the mountain, Eden had demonstrated Aya's hover-bounce down the tracks. Several times.

"Well, it doesn't matter anyway," Kai said. "There aren't any more trains scheduled tonight."

"Don't they run unscheduled trains sometimes?" Pana said.

Kai rolled her eyes. "Maybe once a month. Hardly nervous-making, compared to what we do most nights. Come on!"

She and Eden shot forward into the tunnel mouth. A few of the other Sly Girls stood motionless for a moment, staring after them unhappily.

Aya twisted her flashlight on and urged her board forward. Eden Maru was suspicious of her already; she wasn't about to give the rest of them any reason for doubt.

A one-in-thirty chance wasn't that bad.

In the red light of her beam, dust swirled across the tracks, still unsettled from the train's passage.

A low moan filled the blackness, and her skin prickled. A steady breeze moved through the tunnel, as if the stone walls themselves were breathing.

Aya wondered how they were supposed to find the hidden door. Last night it had looked exactly like the tunnel wall. Maybe surged eyes or Moggle's fancy lenses could tell smart matter and stone apart, but Aya doubted that her normal human vision would be much help.

Miki was already drifting down the tunnel, a flashlight in one hand. She slid her fingers across the wall's surface, peering closely at the stone.

Aya brought her hoverboard alongside. "No infrared, huh?"

"No," Miki sighed. "How about you?"

Aya shook her head. "My crumblies won't let me. But you're sixteen, aren't you?"

"Yeah, but I like my eyeballs."

"They can make them look exactly the same, you know."

"But I like my eyeballs, not an imitation of them. I know that's sort of pre-Rusty."

Aya shrugged. "My brother kicked this natural-body clique who never surge. Some of them have to wear these things like sunglasses just to see, even when they're not out in the sun!"

Miki narrowed her eyes. "Your brother's famous, isn't he?"

"I guess," Aya said, suddenly wishing she hadn't brought up kicking.

"That's why you became a kicker, isn't it? Because of him?"

"That's what Hiro thinks, like I worship him or something. But he's actually an advertisement for not being famous. It turned him into a big snob."

Miki laughed. "You don't have to run your brother down, Aya-chan, just because he's a big face.

We don't hate kickers - we just don't want anyone kicking us."

"Yeah, I get it." Aya shifted on her board, aligning the button camera again. "But a lot of people would love to see us surf, wouldn't they?"

"Yeah, but then everyone would start mag-lev surfing, and the wardens would get involved."

Miki shook her head. "We have to keep this trick ours. You understand that, right?"

"Of course!" Aya insisted, but Miki was still frowning. Maybe it was time to switch gears. "By the way, thanks for sticking up for me."

"No problem. Like I said, I trust you."

Aya turned to study the wall closely, the nervous trickle starting in her stomach again. "Yeah. But I still owe you one."

A tapping sound came from ahead, and they both looked up.

It was Kai, striking the wall with her flashlight as she slid through the air. Her blows echoed down the tunnel, the stone sounding as solid as a mountain.

"So that's our plan for finding the secret door?" Aya said softly. "Banging on the wall?"

"Do you think they could program smart matter to sound like stone?"

"Probably," Aya answered. Ren always said you could program smart matter to do practically anything. It was one of the big inventions since the mind-rain, like AI and internal eyescreens, innovations that the Prettytime had postponed for centuries. "But why would they bother? Whoever made that door wouldn't expect anyone to walk around down here looking for it."

Miki tapped her own flashlight against the stone - it sounded like solid rock. "So if it hadn't been for us mag-lev surfing, no one would ever have found that door." She smiled. "Maybe it's like the Youngblood cults say: Being crim can change the world."

Aya turned toward her, making sure the button cam had a shot. "And how does finding this door change the world?"

"Well ... I guess that depends on what's inside." Miki tapped the stone. "I mean, what if there's something really scary hidden down here?"

"Like a secret toxic waste dump?" Aya smiled. "Think how many merits the Good Citizen Committee would give us for uncovering it."

"Don't say that too loud, Aya-chan. Kai hates merits even more than fame." Miki tapped the wall again. "But thanks for mentioning toxic waste. That should distract me from the unscheduled train I've been imagining."

"Hey, Eden!" someone called. "Come here!"

Ahead, a small cluster of Girls had gathered around a section of the wall, all tapping with their flashlights. Aya and Miki glanced at each other, then urged their boards farther into the tunnel.

As they grew closer, Aya listened hard. Was there was something hollow about the echoing blows?

"Let me past, Nosey," Eden Maru's voice came from behind her.

As Aya slid aside, she saw the device in Eden's hands and her heart began to race. It was a matter hacker.

This wasn't just tricks; this was really illegal. Matter hackers could reprogram smart matter any way you wanted -  there were whole buildings you could hack to the ground if you were crazy enough.

And all she had was this stupid button camera. Shots of an illicit matter hacker would be a total eye-kick.

Aya peered ahead into the darkness, hoping that Moggle was lurking somewhere close. She was dying to check for a signal, but her eyescreen's flicker would be a dead giveaway in the blackness of the tunnel.

The cluster of Sly Girls parted for Eden, all eyes on the small device in her hands. She pressed it against the wall, fingers running over the controls.

After a moment, she nodded. "This is it. Stand back -  there could be anything behind there."

"Or any one," Miki murmured.

Aya thought of the inhuman figures again, their strange faces and long, thin fingers. "But those body-crazy freaks were just storing something down here," she said. "Nobody lives in this place."

Miki shrugged. "I guess we're about to find out."

A humming filled the tunnel as the clever molecules of smart matter began to rearrange themselves - the wall rippled, its texture changing from rough stone to the pearly sheen of plastic. The door's shape came into focus, a rectangle the exact size of a mag-lev cargo door.

Then the wall began to peel aside, one layer after another, like water sliding across a flat surface.

Just as it had the night before, the air tasted tremulous, like a thunderstorm was coming.

The tremors traveled along Aya's skin, as if the matter hacker was changing her as well...

The last layer slipped away, and the door stood open wide before them. A long hallway stretched out ahead, lit with an orange glow.

"Now this is very sly," Kai said, and stepped inside.

THE HIDDEN

The Sly Girls dashed ahead into the mountain hideaway, everyone wanting to be the first to discover what wonders were hidden here. Calls and laughter filled the air, echoing from the bare stone walls.

Aya couldn't see a single right angle, just arches and rounded corners. Every few meters, oval doorways led away to more winding halls, an undulating maze cut into stone.

"Well, whoever lives here is definitely moving out," Miki said.

Aya nodded. The main hallway was crowded with equipment and storage containers, a disorganized jumble covered with a fine layer of dust.

"Maybe we should look for those big metal cylinders," she said. "Those were the only things they were moving in last night."

"As long as whatever we find isn't alive." Miki gestured toward a bunch of work chairs crammed together in the hallway. They were the wrong shape - too high and narrow, suited for some inhuman form.

Aya shone her flashlight down at her feet. A meter-wide path of metal studs glistened from the stone floor, leading straight down the middle of the main hallway. "That's to give hover-lifters something to push against. Anything heavy would have to go this way. Come on."

The two of them followed the metal path with careful, silent footsteps. The arched doorways revealed empty rooms, dust patterns on the floor showing where furniture had been removed.

As they went deeper into the mountain, the echoes of the other girls' voices grew faint around them. Aya wondered how so many tons of rock had been carried away to make this place. Whoever had built it must have tricked the automatic mag-lev trains into taking a lot of cargo for them. Or maybe one of the city governments was involved - this all seemed too big to do on the sly.

Every city had expanded since the mind-rain, pulling the Rusty ruins apart for scrap, scrambling to get more metal.

"Who has the resources to build something like this?" Aya murmured.

"Maybe this was one of those Rusty places where they dug up metal. What were they called...mines?"

Aya realized that they were whispering. Noises reverberated sharply against the bare stone walls, making her conscious of every sound she made.

The long, sleep-missing day was finally catching up with her, a brain-fogging exhaustion erasing the excitement that had propelled her through the mag-lev ride. The dim orange lighting was playing tricks on her eyes. Long shadows leaped from the beams of their flashlights, and Aya doubted her button cam was getting any decent shots.

Suddenly Miki spun around. "Did you see that?"

"See what?"

"I don't know." Miki pointed her flashlight down the hall behind them. "The shadows were moving funny. Like something's following us."

"Something?" Aya said, turning to stare into the darkness. She felt totally awake now.

"Maybe I'm just imagining it."

Aya sighed. "Great. Now I'm imagining it too."

"Come on," Miki said. "I feel like we're getting close to something."

"Is that the same something that's following us? Or a different something?"

Miki shrugged, and moved ahead.

In the next room, the path of metal studs led to a large opening in the wall and a set of stairs leading down. There were no orange worklights below, only blackness.