Nate found shelter in an old firehouse about two miles from the tower.

  The building was intact—brick walls, heavy doors, the kind of construction that had survived the chaos of integration better than most. The trucks were gone, probably commandeered in the early days when people still thought emergency services might save them. But the living quarters upstairs were untouched. Cots, lockers, a small kitchen.

  He secured the entrances, checked for monsters, and allowed himself to stop moving for the first time in what felt like days.

  His body ached. Not from wounds—the level-ups had healed those—but from exhaustion. The bone horde had taken more out of him than he'd realized. Even with D-rank Durability, even with [Iron Body], fighting hundreds of monsters and a boss creature two levels above him had pushed his limits.

  He needed rest. Real rest.

  Nate found a cot that didn't smell too bad and lay down. The ceiling above was water-stained, cracked in places. Familiar. It reminded him of the gym where he'd spent most of his twenties.

  He closed his eyes.

  Sleep didn't come easy.

  His mind kept turning over everything that had happened. The towers. The necromancer. The portal that would open when all six towers were cleared. He was making progress—one tower down, three to go—but every step forward felt like walking toward something he couldn't quite see.

  The necromancer was out there, building her army. Every day he spent clearing towers was another day she grew stronger. But he couldn't ignore the towers either. The monsters pouring out of them were killing people, and every death fed her forces.

  Damned if he did, damned if he didn't.

  He turned onto his side, staring at the wall. A poster hung there, faded and peeling. Fire safety guidelines. A cartoon dalmatian teaching kids to stop, drop, and roll.

  A relic from a world that didn't exist anymore.

  His thoughts drifted backward, to the time before.

  Three years ago, he'd been someone. Not famous, not a champion, but someone. A professional MMA fighter with a 12-3 record, fighting in regional circuits, slowly working his way up the ranks. He'd had sponsors—small ones, but sponsors. A gym that believed in him. A future that seemed, if not bright, at least visible.

  He remembered the feeling of those days. The early mornings, the brutal training sessions, the camaraderie of fighters who understood what it meant to put everything on the line. The rush of stepping into the cage, the crowd noise fading to nothing, the world shrinking down to just you and your opponent.

  He'd been good. Not great, but good. Good enough to dream of more.

  Then came the knee.

  It wasn't even a dramatic injury. No spectacular knockout, no career-ending moment captured on camera. Just a bad landing during training, a twist that shouldn't have mattered, and then pain. The kind of pain that didn't go away.

  Torn ACL. Damaged cartilage. Six months of recovery, minimum. Maybe longer. Maybe forever.

  He'd done the surgery. Done the physical therapy. Spent every penny he'd saved on doctors and treatments and specialists who all said the same thing: you might fight again, but you'll never be what you were.

  He tried anyway. Came back too soon, lost badly, injured the knee again. Came back again, lost again. Each fight worse than the last, each recovery longer, each conversation with his corner more strained.

  The worst part wasn't the losing. It was watching himself become someone he didn't recognize—desperate, angry, clinging to something that was already gone. His friends from the gym started avoiding him. His coaches stopped returning calls. The life he'd built, the identity he'd created, all of it slipping through his fingers like sand.

  Eventually, the gym stopped believing. The sponsors disappeared. The future he'd been working toward crumbled into nothing.

  And then his parents called.

  Nate hadn't thought about that conversation in months.

  He'd been living in a studio apartment, surviving on ramen and stubbornness. His mother's voice had been cold—colder than he'd ever heard it. His father hadn't spoken at all, just sat in the background while she delivered the verdict.

  "We've given you every opportunity," she'd said. "Paid for your training, supported your career, believed in you when no one else did. And what do you have to show for it?"

  He'd tried to explain. The injury. The recovery. The plan to—

  "There is no plan, Nathan. There's just you, throwing your life away on a dream that died years ago."

  "Mom—"

  "Don't. We're done. Your father and I have discussed it, and we can't keep watching you destroy yourself." A pause. A breath. "Don't call again until you've made something of yourself. Until you can look us in the eye and tell us it was worth it."

  The line went dead.

  He'd called back. Once, twice, a dozen times over the following weeks. His mother never answered. His father never answered. Eventually, he stopped trying.

  That was two years before the integration. Two years of working odd jobs, living in shitty apartments, watching his body slowly heal while his soul stayed broken. He'd stopped fighting, stopped training, stopped doing anything except existing.

  When the towers appeared, when the System descended, when the world ended—Nate had walked into the nearest tower because he had nothing left to lose.

  He opened his eyes.

  The ceiling was still there. Cracked, stained, familiar. The firehouse was quiet around him, the only sound his own breathing.

  Nothing left to lose.

  That had been true, once. But was it still?

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  He thought about Tyler and Mira. About Frank and Chen and Rivera. About the hundreds of people at the camp, counting on him to clear the towers, to stop the necromancer, to give them a chance at surviving.

  He thought about the scarred woman from the raiders, staring at him with recognition and fear. "The monster who kills monsters," she'd called him. A story people told to feel better about dying.

  He wasn't nothing anymore. He was something—maybe something terrible, maybe something necessary, but something. People knew his name. People depended on him. People were alive because of choices he'd made.

  But it was more than that.

  For the first time, Nate let himself acknowledge the truth he'd been avoiding.

  He was happy.

  Not happy about the death, the destruction, the millions of people who'd died in the integration. Not happy about the necromancer or the raiders or the endless violence that had become his life. But underneath all of that, buried beneath the guilt and the exhaustion and the weight of responsibility...

  He was fighting again.

  Not in a cage, not for points or rankings or sponsors who'd abandoned him the moment things got hard. Real fighting. The kind of fighting he'd dreamed about as a kid, before MMA became a career, before the politics and the business and the crushing disappointment of a body that betrayed him.

  His knee didn't hurt anymore. His body didn't fail him. Every punch landed exactly where he wanted it, with more power than he'd ever imagined. He was stronger, faster, tougher than any human had ever been. He was fighting monsters—actual monsters—and winning.

  This was what he'd always wanted. Not the specific circumstances, but the essence of it. To test himself against impossible odds. To push beyond his limits. To be the best version of himself in the most demanding arena imaginable.

  The integration had taken everything from the world. But it had given him back his dream.

  Was that selfish? Probably. Millions dead, civilization collapsed, and here he was, secretly grateful for the chance to fight again. What kind of person did that make him?

  He didn't know. But he was done pretending he didn't feel it.

  This was his life now. He was going to live it.

  Was it worth it?

  He thought about his parents. About their disappointment, their cold silence, their demand that he make something of himself.

  Maybe this wasn't what they'd meant. But it was something. More than he'd been before. And for the first time in years, he felt like he was exactly where he was supposed to be.

  That had to count for something.

  Sleep came eventually.

  It was deep and dreamless, the kind of sleep that only comes from true exhaustion. His body repaired itself in ways the System couldn't—the micro-tears in muscles, the accumulated fatigue in bones and joints, the mental strain of constant violence.

  When he woke, light was filtering through the firehouse windows. Morning. He'd slept through the night.

  Nate sat up slowly, taking stock of himself. The aches were gone. His mind felt clearer than it had in days. He was hungry—genuinely hungry, not just aware that he should eat.

  He found his pack, pulled out a ration bar, and ate it while watching the sunrise through a grimy window. The sky was red and orange, streaked with clouds that might have been beautiful if they didn't remind him of fire and blood.

  Strange, how the world could still be beautiful. Even now, even after everything, the sun rose and set like it always had. The sky didn't care about integration or monsters or the dead walking. It just kept going.

  Maybe that was the lesson. Keep going. No matter what.

  His parents had wanted him to be something. To make something of himself, they'd said. He wondered what they'd think if they could see him now. Level 23. Killer of monsters. Protector of survivors.

  Was this what they'd meant? Probably not. But it was something. More than he'd been before.

  Another day. Another tower.

  Before he left, he tested the new skill.

  The firehouse had a small gym in the back—weights, a punching bag, the kind of equipment firefighters used to stay in shape. The bag was old but intact, filled with sand that had compacted over the years into something almost as hard as concrete.

  Nate stood in front of it, rolled his shoulders, and focused.

  [Bone Breaker].

  The knowledge was there, integrated into his muscle memory like he'd always known it. A way of striking that concentrated force into a narrow point, that found weaknesses in armor and exploited them. He could feel the skill waiting, ready to be used.

  He threw a punch.

  The bag didn't swing—it exploded. Sand erupted from the impact point, spraying across the gym. The chain holding the bag snapped, and the whole thing flew backward, hitting the wall hard enough to crack the brick.

  Nate stared at his fist. Then at the destroyed bag. Then at the crack in the wall.

  He'd hit bags before. Hit them thousands of times, with every technique he knew. He'd never done anything like that.

  [Bone Breaker] wasn't just an upgrade. It was a transformation. His strikes had always been powerful—D-rank Strength and [Pressure] made sure of that. But this was something else. This was a skill designed to break things that didn't want to break.

  Armored opponents. Skeletal creatures. Things with defenses that should have been impenetrable.

  He thought about the Ossuary Crawlers, with their layered ribcage shells. Thought about the Bone Colossus, with its fused skeleton armor.

  With [Bone Breaker], those fights would have been easier. A lot easier.

  What would the next tower throw at him?

  He smiled, flexing his fingers.

  Only one way to find out.

  The next tower was six miles northwest.

  Nate moved quickly, refreshed from his rest, eager to test his new skill against real opponents. The route took him through industrial areas—factories and warehouses, train yards and shipping depots. Most of it was abandoned, but he spotted signs of habitation in places. Smoke from distant fires. Barricades around certain buildings. The marks of survivors who'd found their own ways to hold on.

  He didn't stop. Didn't investigate. He had a mission, and every hour he delayed was another hour the necromancer had to build her forces.

  The monsters were thinner here than they'd been near the first tower. He passed a few packs of scavenger hounds, but they fled before he got close. Word was spreading, maybe. Or maybe they could sense what he'd become.

  Level 23. D-rank Strength and Durability. Five skills, including one specifically designed to break armored targets.

  He wasn't the same man who'd walked into his first tower a month ago. Wasn't even the same man who'd walked out of it.

  For better or worse, he was becoming something else.

  The tower appeared on the horizon around noon.

  This one was different from the others. Where his tower had been black stone and the Bone Spiral had been pale white bone, this one was metal. Dark iron, corroded and ancient, rising from the earth like a massive spike. Rust streaked its surface in patterns that almost looked intentional—symbols or writing, worn away by time until only suggestions remained.

  [Tower of the Iron Rot]

  [Status: Open]

  [Warning: Tower deadline exceeded. All restrictions lifted.]

  Another opened tower. Another horde waiting outside.

  Nate slowed his approach, scanning the area around the tower's base. The terrain here was different—an old rail yard, filled with abandoned train cars and rusting equipment. Plenty of cover. Plenty of places for things to hide.

  He saw movement among the train cars. Shapes that glinted in the afternoon light. Metal on metal, scraping and grinding.

  The monsters here weren't made of bone.

  [Rust Stalker — Level 15]

  [Rust Stalker — Level 14]

  [Iron Crawler — Level 17]

  [Corroded Beast — Level 18]

  Metal creatures. Rusted iron fused into bodies that moved with grinding, screeching motions. They were emerging from the shadows between train cars, drawn by his presence, converging on his position.

  Dozens of them. Maybe hundreds.

  And at the center of the rail yard, in front of the tower entrance, something massive was starting to stir.

  Nate cracked his knuckles.

  [Bone Breaker] might have been designed for skeletal opponents—but armor was armor. Let's see how it worked on metal.

  He walked toward the horde.

  "Round two," he said.