The sun was high and cruel, baking the valley until the air shimmered.
"Okay," Kai said. He stood with his back to the chasm, his outline sharp against the empty sky. "Let's begin. But there are rules. You follow them without questions."
Elara wiped sweat from her forehead. "What rules?"
"First: don't cross the board. Ever. Not even a toe on the other side." He pointed at the weathered wooden post. "Second—especially you, Elara—don't cross your line and ask about your sister."
Elara stiffened. "I didn't—"
"You will. Don't." His eyes were hidden behind the black lenses, unreadable. "Third: do exactly what I say. When I say stop, you stop. When I say run, you run."
Bati shifted her weight. "It sounds like we're joining the army."
"It sounds like we're going to die," Rose muttered, but she was smiling.
Kai ignored them. He stepped forward, rolling his shoulders. "The band you're wearing—it's programmed with high-level tech. Step back and watch."
They retreated a few paces. Kai extended his left arm, palm up.
"It can be controlled two ways," he said. "Brain, or manual."
"We know brain control," Bati said. "You focus carefully. But we didn't know it could be manual."
"Brain is safer," Kai said. "More powerful. More precise. But it takes training."
He closed his eyes. His hand twitched once, slowly. A soft green light pulsed from his band—not the harsh blue they were used to, but something deeper, older. The metal flowed, reshaping into a sleek pistol.
He raised it. Aimed at a distant boulder.
The laser was silent. The rock exploded into dust.
"That's brain control," Kai said. "Simple. Clean."
He shook his hand again. The pistol melted, expanded, became a massive launcher that dwarfed his arm. The green light intensified, humming like a hornet's nest.
"Or complex," he said.
He fired.
The beam was a perfect circle of destruction, white-hot at the center, carving a crater ten feet wide into the earth. The ground shook. Smoke rose in a lazy spiral.
Rose whistled low. "Show-off."
"Now manual," Kai said. He turned to Rose. "Show me your band."
She extended her arm, the silver cuff catching the sun. Kai reached out and placed his hand over hers.
"Look."
His fingers tightened. Rose's band flared blue, then shifted—without her command—morphing into a launcher identical to his. She gasped, trying to pull away, but his grip was iron.
"Hey—"
"Fire," Kai said.
The launcher discharged, the blast tearing through a tree trunk fifty yards away. The wood splintered and fell.
"Again," Kai said.
"Wait, I can't—"
He forced her arm up. The launcher fired again, then again, Rose's finger twitching against the trigger she wasn't pulling. Her face went pale.
"Kai, stop!" Elara shouted.
He didn't look at her. "Manual control is dangerous," he said calmly. "Because the person who originally programmed the band? They're stronger. They can override. They can take it back."
Rose was trembling now, her arm jerking as Kai manipulated it remotely, aiming the weapon at the sky, then at the ground, then—horrifyingly—back toward her own chest.
"Kai!" Elara grabbed his shoulder.
He released Rose's wrist. The launcher vanished instantly. Rose stumbled back, cradling her arm like it was burned.
"Never use manual unless you have no choice," Kai said, his voice flat. "If you do, you're trusting someone else not to take control. Now. Focus your minds. Try something other than cars. You all make cars because it's easy. It's lazy. Try weapons. Try tools. Try anything that requires precision."
They practiced.
The hours crawled by. The sun crossed the sky, merciless. Elara's shirt stuck to her back. Her throat was dust. She managed to make simple blade— then nothing but a misshapen lump of metal that dissolved back into her band.
Bati managed a small energy pistol, but it misfired and burned her palm. She sucked on the wound, tears in her eyes, and tried again.
Rose had the most success—a shield, flimsy and translucent, that shattered after one hit.
Kai didn't praise them. He didn't criticize. He just watched, arms crossed, occasionally correcting their stance with a sharp prod to the shoulder or a kick to the ankle.
"Elara. You're thinking about the shape. Don't. Think about the function. What does a blade do? It cuts. Feel the cutting."
"I can't—"
"Again."
By evening, they could each produce a small energy dagger—unstable, flickering, but sharp. They stood in the dying light, bruised and sunburned, holding their pathetic weapons like trophies.
"Pack up," Kai said. He shook his hand. The car formed—sleek, black, humming. "Let's go."
They piled in, too tired to complain about the seats. Kai drove. The valley disappeared behind them, replaced by the flat expanse of the green fields, then the first flickering lights of the city.
Elara leaned her head against the window. Her muscles screamed. But her mind was awake, turning over the day like a stone in her palm.
"Kai," she said quietly.
He didn't answer. The car ate up the miles.
"Why does your band glow green? Ours is blue. Everyone's is blue."
The silence stretched. Outside, the first stars were appearing.
"After an incident," Kai said finally. "It changed."
"What incident?"
"Don't cross your line, Elara."
Bati leaned forward from the back seat. "I have a question too. Why do you always wear those black glasses? Even inside. Even at night."
Kai's jaw tightened. "Personal. I don't answer personal questions."
"But—"
Rose touched Bati's knee, shaking her head. She turned to Kai, her voice light, teasing. "Okay, okay. My turn. How strong can you make armor from your band? Like, really strong?"
Kai glanced at her in the rearview mirror. "Why do you want to know?"
"Curiosity. You seem to know everything about these things. You must have tested the limits."
Kai was quiet for a long moment. The city lights reflected in his lenses.
"You know why your father asked me to train you?" he asked Elara.
She turned to look at him. "Because I asked him."
"You think he'd ask a common factory worker to train his precious daughter? Just because you asked nicely?"
Elara frowned. "Then why?"
"Do you know about the Red Death Arena?"
The car went silent. Even the engine seemed to quiet.
Rose's breath hitched. "Oh. Oh, hell."
"What?" Bati looked between them. "What is that?"
"It was a game," Rose said quietly. "Between Alpha and Beta. A death match. Prisoners, volunteers, people who owed debts... they fought in an arena. To the death. For entertainment."
"They closed it down," Bati said. "I remember hearing about it. It was years ago."
"They closed it," Rose said, "because of one participant. The last survivor. The one who didn't just win—he destroyed the whole arena. "
Elara felt cold despite the heat. She looked at Kai's profile—the sharp jaw, the black glasses, the green light pulsing faintly on his wrist.
"That was you," she whispered.
Kai didn't confirm. He didn't deny. He just kept driving, his hands steady on the wheel.
"It started," he said, "when ..."
The car sped into the night, carrying them toward the memory of blood.