The ride back to the Rusty Spire was quiet.
Too quiet.
On the way out, Vex had been blasting pre-war rock music and cracking jokes about tetanus. Now, the only sound inside The Coffin was the roar of the engine and the rattle of loose bolts.
I sat in the back, staring at my right hand.
The black veins had faded, retreating deep under my skin, but the sensation remained. It felt like my arm had been dipped in liquid nitrogen. A cold, numbing buzz that traveled up my shoulder and settled in the base of my neck.
I wasn't tired. That was the scary part. I had been awake for thirty hours. I had climbed a mountain of trash. I had been punched by a bio-weapon. But I felt... electric.
My senses were dialed up to eleven. I could hear the heartbeat of Mink sitting across from me. Thump-thump. Thump-thump. I could smell the ozone on Jax's armor. I could see the dust motes dancing in the dim light of the cabin.
I clenched my fist. The metal bench beneath me groaned as I accidentally crushed the edge of the seat.
Jax flinched.
The giant, who had laughed while firing a rotary cannon at Scavengers, shifted his weight away from me. He kept his hand near his holster.
"Relax, big guy," I muttered, my voice sounding raspier than usual. "I'm not going to eat you."
Jax didn't smile. "That thing back there... it didn't die, Ghost. It unraveled. I've never seen entropy move that fast."
"Leave him alone," Lyra said sharply. She was sitting next to me, her shoulder pressing against mine. It was a calculated move. She was showing them—and me—that she wasn't afraid.
But I could feel her trembling.
"We have the generator," Lyra said, looking at Vex's reflection in the rearview mirror. "We have the food. We did the job. Kairo is the reason we're rich."
Vex was silent for a long moment. He navigated the rover around a burning pile of tires before speaking.
"Yeah," Vex said, his voice devoid of its usual manic energy. "He did the job. Just remind me never to piss him off."
We arrived at the Rusty Spire an hour later.
The mood inside the fortress changed the moment the bay doors opened. When the people of the Spire saw the crates of fresh water, ration packs, and the massive fusion generator, a cheer went up that shook the rust off the ceiling.
"Fresh water!" "Real power cells!"
Dozens of people swarmed the vehicle. Mechanics, mothers, children—they looked at the haul like it was treasure. They clapped Jax on the back. They lifted Mink onto their shoulders.
I stepped out of the back of the truck and leaned against a pillar, staying in the shadows.
I felt... disconnected. Watching them cheer felt like watching a movie through a dirty screen. The Hunger inside me was quiet, but it was there, purring like a sleeping cat. It wanted more energy. It wanted more green fluid.
"You look like hell," a voice said.
Mink was standing next to me. She wasn't celebrating. She was holding her tablet, scanning me.
"Your body temperature is dropping," she whispered, tapping the screen. "You're at 94 degrees. And your neural activity... Kairo, your brain waves are syncing with the background radiation of the Underside."
"Is that bad?" I asked.
"It's weird," she corrected. "It's like you're becoming part of the environment."
She reached into her pocket and pulled out a small, foil-wrapped bar. It was chocolate. Real, pre-war chocolate. Probably worth more than gold down here.
"Vex gave it to me for hacking the door," she said, breaking it in half. She handed me the bigger piece. "Eat. You burn calories fast when you... do whatever you do."
I took the chocolate. My hand was shaking. "Thanks, Mink."
"Don't get used to it," she muttered, adjusting her goggles to hide her eyes. "I just don't want my best asset passing out."
She scurried away before I could answer.
"Asset," I whispered to myself, taking a bite. The sugar hit my system, and for a second, the cold in my chest receded.
"They're afraid of you, you know."
I looked up. Lyra was standing on the catwalk above me, leaning on the railing. She signaled for me to come up.
We climbed to the roof of the Spire—the highest point in the Underside. From here, the trash mountains looked like dark waves in a frozen ocean. Far above, the crack in the ceiling—the Sky Bridge—was just a faint scar.
Lyra sat on the edge, dangling her legs over the abyss. I sat next to her.
"I don't blame them," I said. "I'm afraid of me."
"It felt good, didn't it?" Lyra asked softly. "When you took its energy."
I hesitated. I wanted to lie. I wanted to say it was painful, or gross. "It felt... perfect," I admitted. "Like taking a breath after holding it for seventeen years."
Lyra picked up a piece of gravel and threw it into the dark.
"That's the trap, Kairo. The Black Echo... it's a predator. Predators don't stop hunting just because they're full."
She turned to me, her grey eyes serious.
"You need to learn to control the hunger. If you don't, one day you'll reach for an enemy, and you'll grab a friend instead."
The thought made my stomach turn. I looked at my hand, imagining it turning Lyra into ash.
"I won't let that happen," I swore.
"Good," a mechanical voice rasped from behind us.
Vex stepped out of the shadows. He wasn't smiling. He was holding two bottles of amber liquid. He tossed one to me.
"Scavenger brew," Vex said. "Tastes like battery acid, but it kills the pain."
He sat down on a crate opposite us. He took a long swig from his bottle, wiped his mouth, and sighed.
"You kept your word, Null. You got us the generator. The Spire will have heat for five years because of you."
"We had a deal," I said, putting the bottle down without drinking. "The generator for information."
Vex nodded. The playful glint in his mechanical eye was gone. He looked old. Tired.
"The Dark Eater," Vex whispered.
"You said you saw it," I pressed.
"I didn't see it," Vex corrected. "I heard it. And I saw what it left behind."
He leaned forward, lowering his voice as if the wind might be listening.
"Three years ago, before the Admin started the countdown, there was another Null who fell into the Underside. A girl."
My heart skipped a beat. "A girl? Like me?"
"No," Vex shook his head. "She was worse. She was broken. She fell down here screaming. She couldn't control the deletion. She touched the ground, and the ground vanished. She touched the water, and the water burned."
He took another drink, his hand shaking slightly.
"She went mad, Kairo. The hunger ate her mind. She ran into the Deep Tunnels—Sector Negative-One. And now? Now she is the Dark Eater. A living storm of deletion that wanders the dark."
Vex pointed a dirty finger at me.
"That's your future, kid. If you don't find a way to fix yourself... you're just a baby Dark Eater waiting to grow up."
I stared at him. A chill that had nothing to do with the wind swept over me.
"Is she still alive?" I asked.
"Alive? No. Dead? No." Vex shrugged. "She's just Hunger."
"Why are you telling me this?"
"Because," Vex said, standing up. "If you want to know what you are, you need to find her. And I know where the entrance to Sector Negative-One is."
He turned to leave, pausing at the door.
"Rest up, Ghost. Tomorrow, we start training. If you're going to face the Dark Eater... you're going to need more than just a hungry hand."