Tally tried to answer, but her throat was dry.
'Listen, if you don't want to come, that's fine,' Shay said. 'I mean it, Squint. But we're not going to get caught. And if we do, I'll take the blame.' She laughed. 'I'll tell them I kidnapped you.'
Tally stepped onto her board and snapped her fingers. When she reached Shay's eye level she said, 'I'm coming. I said I would.'
Shay smiled and took Tally's hand for a second, squeezing. 'Great. It's going to be fun.
Not new pretty fun-the real kind. Put these on.'
'What are they? Night vision?'
'Nope. Goggles. You're going to love the white water.'
They hit the rapids ten minutes later.
Tally had lived her whole life within sight of the river. Slow-moving and dignified, it defined the city, marking the boundary between worlds. But she'd never realized that a few kilometers upstream from the dam, the stately band of silver became a snarling monster.
The churning water really was white. It crashed over rocks and through narrow channels, catapulted up into moonlit sprays, split apart, rejoined, and dropped down into boiling cauldrons at the bottom of steep falls.
Shay was skimming just above the torrent, so low that she lifted a wake every time she banked.
Tally followed at what she guessed was a safe distance, hoping her tricked-up board was still reluctant to crash into the darkness-cloaked rocks and tree branches. The forest to either side was a black void full of wild and ancient trees, nothing like the generic carbon-dioxide suckers that decorated the city. The moonlit clouds above glowed through their branches like a ceiling of pearl.
Every time Shay screamed, Tally knew she was about to follow her friend through a wall of sprayleaping up from the maelstrom. Some shone like white lace curtains in the moonlight, but others struck unexpectedly from the darkness. Tally also found herself crashing through the arcs of cold water rising from Shay's board when it dipped or banked, but at least she knew when a turn was coming.
The first few minutes were sheer terror, her teeth clenched so hard that her jaw ached, her toes curled up inside her special new grippy shoes, her arms and even fingers spread wide for balance. But gradually Tally grew accustomed to the darkness, the roar of water below, the unexpected slap of cold spray against her face. It was wilder, and faster, and farther than she'd ever flown before. The river wound into the dark forest, cutting its serpentine route into the unknown.
Finally, Shay waved her hands and pulled up, the back of her board dipping low into the water. Tally climbed to avoid the wake, spinning her board in a tight circle to bring it to a smooth halt.
'Are we there?'
'Not quite. But look.' Shay pointed back the way they'd come.
Tally gasped as she took in the view. The distant city was a bright coin nestled in darkness, the fireworks of New Pretty Town the barest cold-blue shimmer. They must have climbed a long way up; Tally could see patches of moonlight rolling slowly across the low hills around the city, pushed along by the light wind that barely tugged at the clouds.
She'd never been beyond the city limits at night, had never seen it lit up like this from afar.
Tally pulled off her spattered goggles and took a deep breath. The air was full of sharp smells, evergreen sap and wildflowers, the electric smell of churning water.
'Nice, huh?'
'Yeah,' Tally panted. 'Much better than sneaking around New Pretty Town.'
Shay grinned happily. 'I'm really glad you think so. I've been wanting to come out here so bad, but not alone. You know?'
Tally looked at the surrounding forest, trying to peer into the black spaces between the trees. This was really the wild, where anything could be hidden, not a place for human beings. She shivered at the thought of being there alone. 'Where to now?'
'Now we walk.'
'Walk?'
Shay eased her board to the shore and stepped off. 'Yeah, there's a vein of iron about half a kilometer that way. But nothing between here and there.'
'What are you talking about?'
'Tally, hoverboards work on magnetic levitation, right? So there's got to be some kind of metal around or they don't hover.'
'I guess so. But in town-' 'In town, there's a steel grid built into the ground, no matter where you go. Out here, you have to be careful.'
'What happens if your board can't hover anymore?'
'It falls down. And your crash bracelets don't work either.'
'Oh.' Tally stepped from her board and held it under one arm. All her muscles were sore from the wild ride here. It was good to be on solid ground. The rocks felt reassuringly the-opposite-of-hovery under her shakey legs.
After a few minutes' walking, though, the board started to grow heavy. By the time the noise of the river had faded to a dull roar behind them, it felt like a plank of oak under her arm.
'I didn't know these things weighed so much.'
'Yeah, this is what a board weighs when it's not hovering. Out here, you find out that the city fools you about how things really work.'
The sky was getting cloudier, and in the darkness the cold seemed more intense. Tally hoisted the board up to get a better grip, wondering if it was going to rain. She was already wet enough from the rapids. 'I kind of like being fooled about some things.'
After a long scramble through the rocks, Shay broke the silence. 'This way. There's a natural vein of iron underground. You can feel it in your crash bracelets. '
Tally held out one hand and frowned, unconvinced. But after another minute she felt a faint tugging in her bracelet, like a ghost pulling her forward. Her board started to lighten, and soon she and Shay had hopped on again, coasting over a ridge and down into a dark valley.
Onboard, Tally found the breath to ask a question that had been bugging her. 'So if hoverboards need metal, how do they work on the river?'
'Panning for gold.'
'What?'
'Rivers come from springs, which come from inside mountains. The water brings up minerals from inside the earth. So there's always metals at the bottom of rivers.'
'Right. Like when people used to pan for gold?'
'Yeah, exactly. But, actually, boards prefer iron. All that glitters is not hovery.'
Tally frowned. Shay sometimes talked in a mysterious way, like she was quoting the lyrics of some band no one else listened to.
She almost asked, but Shay came to a sudden halt and pointed downward.
The clouds were breaking, and moonlight shot through them to fall across the floor of the valley. Hulking towers rose up, casting jagged shadows, their human-made shapes obvious against the plain of treetops rippling in the wind.
The Rusty Ruins.
A few blank windows stared down on them in silence from the husks of the giant buildings. Any glass had long since shattered, any wood had rotted, and nothing remained but metal frames, mortar, and stone crumbling in the grip of invading vegetation. Looking down at the black, empty doorways, Tally's skin crawled with the thought of descending to peer into one.
The two friends slid between the ruined buildings, riding high and silent as if not to disturb the ghosts of the dead city. Below them the streets were full of burned-out cars squeezed together between the looming walls. Whatever had destroyed this city, the people had tried to escape it. Tally remembered from her last school trip to the ruins that their cars couldn't hover. They just rolled along on rubber wheels. The Rusties had been stuck down
