The Rusty Spire had a heartbeat now.
It was a low, rhythmic thrum-thrum-thrum that vibrated through the metal floor plates. It was the sound of the Fusion Generator we had stolen, pumping heat and light into the vertical city.
I woke up on a pile of old mattresses in a corner of the mechanics' bay. For the first time in days, I wasn't shivering. The air was actually warm.
But I didn't feel warm. Inside, I felt like a hollowed-out battery.
The "high" from absorbing the Bio-Weapon was gone. It had burned off during the night, leaving a gnawing emptiness in my chest. My Black Echo was dormant again, curled up in my shadow like a starving dog waiting for a scrap of meat.
"You're awake," a voice grunted.
Jax was standing over me. Without his massive armor, he looked almost human—a mountain of scars and muscle in a grease-stained tank top. He tossed a heavy metal pipe at me.
I caught it, but the weight nearly pulled my arm out of its socket.
"Get up, Ghost," Jax said. "Vex says it's time to see if you can fight something that doesn't hold still."
They took me to the Basement.
It was a drained industrial cistern, a massive concrete bowl stained with oil and old blood. Floodlights—powered by my generator—blazed overhead, illuminating the scratched walls.
Vex stood on the rim of the pit, looking like a roman emperor in a junkyard. Lyra sat next to him, cleaning her knife.
"The rules are simple," Vex shouted down to us. "No killing. No maiming. And absolutely no turning anyone into ash."
He pointed a finger at me. "That means you, Null. You use the Echo to disable, not to delete. If you eat Jax, I don't have anyone to carry the heavy crates."
I stood in the center of the pit, gripping the metal pipe. My palms were sweating. "I don't know how to control it," I yelled back. "It's not a switch. It's an instinct."
"Then learn," Vex said coldlly. "Because out in the Boneyard, instinct gets you killed. Control keeps you alive."
Jax stepped into the ring. He wasn't wearing his power armor, but he was wearing a heavy exoskeletal frame on his arms—hydraulic pistons designed to amplify his punches.
He cracked his knuckles. "Don't worry, little ghost. I won't break anything important."
Jax didn't wait for a bell. He charged.
He moved surprisingly fast for a giant. I dodged left, but his reach was insane. The hydraulic arm clipped my shoulder, spinning me around.
I slammed into the concrete wall, gasping for air.
"Too slow!" Jax roared, swinging again.
I rolled under his fist. The concrete where my head had been exploded into dust. I swung the metal pipe, aiming for his ribs. It connected with a solid clung, but Jax didn't even flinch. He just grabbed the pipe, ripped it out of my hands, and tossed it aside like a toothpick.
Then he backhanded me.
The world spun. I hit the ground hard, tasting blood.
"Get up!" Lyra's voice cut through the ringing in my ears. "Stop fighting him physically! You can't beat physics, Kairo!"
Jax loomed over me, blocking the light. "Is that it?" he growled. "You're tough when you're stealing magic from monsters, but take that away, and you're just a soft city boy."
He raised his fist for a finishing blow.
My heart hammered. Fear spiked. And with the fear... came the Hunger.
The cold rushed into my veins. My shadow darkened, swirling around my boots. The Black Echo woke up, smelling the threat.
"FEED," it whispered.
I looked at Jax. I saw the hydraulic pistons on his arms. I saw the blue battery pack glowing on his belt, powering the suit.
I didn't need to hurt him. I just needed to hurt his power.
I rolled forward, diving straight into his guard.
"Suicide move!" Vex shouted.
Jax swung down, but I was already inside his reach. I didn't punch him. I grabbed the hydraulic servo on his right elbow.
I unleashed the Echo.
I didn't let it go fully—I didn't want to eat his arm. I just opened the valve a fraction of an inch. I pictured a straw instead of a mouth.
Siphon.
Black sparks flew from my fingertips. The blue light on Jax's battery pack flickered violently.
"DRAIN."
The energy surged into me—a quick, sharp jolt of electricity, like licking a 9-volt battery. Jax's suit whined. The hydraulics seized up instantly.
"What the—" Jax grunted.
His arm froze in mid-air, locked by the dead servo. The weight of the unpowered metal dragged him off balance.
He stumbled.
I didn't stop. I swept his leg, using the momentum of his own frozen suit against him. The giant crashed to the floor with a sound like a falling building.
I stood over him, my hand hovering near his face, black smoke curling from my fingers. I was breathing hard, my eyes glowing faintly with the stolen blue light.
The Basement was silent.
Jax struggled, but his suit was dead weight. He couldn't move his arms.
"I win," I wheezed.
Vex started clapping slowly from the rim.
"Not bad," Vex called out. "You didn't eat him. You just... turned him off."
Jax groaned, finally hitting the emergency release on his suit. The heavy metal frame clattered to the floor, and he sat up, rubbing his elbow.
He looked at me. He wasn't angry. He looked impressed.
"You drained the battery," Jax muttered. "You didn't touch the flesh. You targeted the current."
"I tried to picture a straw," I admitted, the black smoke fading from my hand. "Just a sip."
Lyra jumped down into the pit, handing me a towel. She looked at the dead exo-suit, then at me.
"That's useful," she said, her mind already tactical. "Scavengers run on batteries. Obelisk drones run on batteries. If you can kill their power without destroying the hardware..."
"We can loot them intact," Vex finished, sliding down the ladder. He walked over to the dead suit and kicked it. "Clean kill. No mess."
He looked at me, his mechanical eye spinning.
"But draining a battery is easy, Ghost. Electricity is pure. It wants to flow."
Vex's face darkened.
"The Dark Eater... she doesn't drain batteries. She drains reality. Matter. Light. Time."
He walked closer, his voice dropping to a whisper.
"To beat her, you can't just sip. You're going to have to learn how to swallow the world without choking on it."
"How do I practice that?" I asked.
Vex grinned, revealing his metal teeth.
"You don't practice it here. Tonight, we go deeper. We're going hunting in the Gray Zone."
"Hunting for what?"
"Scavengers," Vex said. "Lots of them. You're going to learn how to fight a pack. Because if you want to find the entrance to Sector Negative-One... you have to go through the Machine King's territory first.