Marko Duskborn

  Trial Key

  A System Apocalypse LitRPG

  First published by Mithril Axe Publishing LLC 2026

  Copyright © 2026 by Marko Duskborn

  All rights reserved. No part of this publication may be reproduced, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise without written permission from the publisher. It is illegal to copy this book, post it to a website, or distribute it by any other means without permission.

  This novel is entirely a work of fiction. The names, characters and incidents portrayed in it are the work of the author's imagination. Any resemblance to actual persons, living or dead, events or localities is entirely coincidental.

  Marko Duskborn asserts the moral right to be identified as the author of this work.

  Third edition

  This book was professionally typeset on Reedsy

  Find out more at reedsy.com

  Contents

  Author Notes

  Foreword

  1. CHAPTER 1: THE JUNGLE OF NERVES

  2. CHAPTER 2: THE ECONOMY OF DEATH

  3. CHAPTER 3: THE VERTICAL MARCH

  4. CHAPTER 4: THE REAR GUARD

  5. CHAPTER 5: THE GLITCH

  6. CHAPTER 6: SCAVENGERS

  7. CHAPTER 7: THE CHECKPOINT

  8. CHAPTER 8: HALL OF MEMORIES

  9. CHAPTER 9: THE SHADOW SELF

  10. CHAPTER 10: SACRIFICE

  11. CHAPTER 11: THE BETRAYAL SHARD

  12. CHAPTER 12: THE SPLIT

  13. CHAPTER 13: JACE’S STAND

  14. CHAPTER 14: CONVERGENCE

  15. CHAPTER 15: THE GLITCH LAYER

  16. CHAPTER 16: THE CULLING

  17. CHAPTER 17: THE SUMMIT APPROACH

  18. CHAPTER 18: THE FALSE KING

  19. CHAPTER 19: THE FINAL BOSS

  20. CHAPTER 20: THE ADMIN CONSOLE

  21. CHAPTER 21: REWRITING THE RULES

  22. CHAPTER 22: NEW GAME PLUS

  Afterword

  Endgame Earth Series

  Author Notes

  This book has been revised. Revision from January 14th, 2026.

  Marko Duskborn

  Foreword

  Welcome back to the end of the world.

  When I started writing the Endgame Earth series, I always knew the Tower of Teeth was looming on the horizon. In the genre of LitRPG, towers are a staple—a vertical crucible where numbers go up and weak characters get weeded out. But for Alec West and Unit 1, I didn’t want this climb to just be about higher stats or better loot (though, let’s be honest, The Sins of Bastion is a pretty sweet drop).

  Book 5 is about the difference between a Gamer and a Leader.

  We’ve watched Alec struggle with the burden of command since the first pulse of mana hit the Cascades Relay Station. He’s made mistakes. He’s lost people. But in Trial Key, he faces a mirror image of what he could become. Warlord Vane isn’t just a boss with a big health bar; he’s the seductive idea that efficiency is worth the cost of humanity. He is the player who skips the cutscenes and min-maxes his empathy into the ground.

  Writing this book was a marathon. The psychological trials of the Mirror Maze , the sheer physical grind of the Verticality , and the meta-physical battle in the Source Code stretched these characters to their absolute limits. I wanted to explore what happens when you strip away the armor and the levels and ask: Who are you when the System isn’t watching?

  For Jace, Rina, Virgil, Eleanor, and Alec, the answer is simple: They are a family. And families carry each other, even when the gravity is crushing them.

  So, equip your best gear, chug a mana potion, and look up. The summit is waiting, and the Administrator is online.

  See you at the top.

  1

  CHAPTER 1: THE JUNGLE OF NERVES

  The mist that separated the first floor from the second wasn’t just water vapor. It was cold, gray, and tasted like static electricity on the tongue. It swirled around Alec West’s boots as he climbed the spiral staircase, obscuring his vision, muffling the sound of his squad’s labored breathing.

  He kept his fire axe in his right hand, the grip slick with the sweat of the Antechamber standoff. His left hand hovered near his belt, ready to draw a mana potion, though he only had two left.

  “Watch your spacing,” Alec whispered, his voice sounding flat in the dense fog. “If something grabs you, sound off immediately. Do not try to be a hero.”

  “I couldn’t be a hero if I wanted to,” Jace wheezed from behind him. The big man’s footsteps were heavy, uneven. The combat stimulant Eleanor had injected him with in the plaza was still flooding his system, masking the pain of his shredded constitution, but the cost was visible in the tremors shaking his hands. He was moving like a machine running on red-lining gears.

  “Just keep moving, big guy,” Rina said softly, her position guarding the rear. “One foot in front of the other.”

  They climbed. The stairs—made of the same pristine white bone as the Antechamber—seemed to go on forever.

  Then, the mist thinned.

  The temperature spiked.

  In the Antechamber, the air had been cool, sterile, smelling of ozone and ancient stone. Here, the air was hot. Wet. Thick with a humidity that felt like breathing through a warm, damp towel.

  And the smell.

  It hit Alec like a physical blow—a cloying, sweet stench of rotting meat, copper blood, and bile.

  “Clear,” Virgil choked out, gagging. “We’re clear of the fog.”

  Alec stepped off the last stair onto a surface that squelched.

  He stopped. He looked down.

  The floor wasn’t stone. It was pink, fibrous, and pulsing.

  [FLOOR 2: THE JUNGLE OF NERVES]

  [ENVIRONMENTAL HAZARD: BIOLOGICAL TERRAIN]

  [DIFFICULTY: NIGHTMARE]

  Alec looked up.

  They weren’t in a room anymore. They were in a biome.

  The ceiling was lost in a canopy of darkness hundreds of feet above. Stretching out before them was a forest. But the trees weren’t wood. They were massive, twisting bundles of gray and white cables that looked disturbingly like enlarged nerve fibers. The trunks twitched rhythmically. The “leaves” were broad, translucent membranes that dripped a viscous, yellow fluid.

  The ground was a carpet of muscle tissue, veined with blue and red capillaries that glowed faintly in the gloom.

  “It’s… alive,” Eleanor whispered, stepping onto the muscle-floor. She looked horrified. “The whole floor is alive.”

  “It’s a biomechanical nightmare,” Virgil corrected, scanning the area with his rifle raised. “Look at the vines. Those aren’t vines. They’re tendons.”

  “Vane came this way,” Alec said, pointing to the ground.

  The muscle-floor was scarred. Boot prints were stamped deep into the tissue. Scorch marks marred the pink flesh. A few of the nerve-trees had been hacked apart, leaking a milky white fluid that hissed where it touched the ground.

  “He cleared a path,” Rina said, kneeling to inspect a severed tendon-vine. “But not a wide one.”

  Sizzzz.

  A drop of liquid fell from the canopy above. It landed on Alec’s pauldron.

  Smoke curled up. The ceramic composite of his armor hissed and pitted.

  “Acid!” Alec shouted. “Take cover!”

  The rain started.

  It wasn’t a downpour; it was a slow, rhythmic dripping from the membrane leaves above. But every drop was corrosive.

  “Under the overhang!” Jace yelled, pointing to a massive, calcified ribcage that jutted out of the ground like a natural archway.

  They sprinted. The ground shifted under their feet, the muscle fibers contracting as they ran, trying to trip them.

  Alec slid under the bone arch, dragging Eleanor with him. Virgil and Rina dove in a second later. Jace crashed in last, smoke rising from his heavy plate where the rain had caught him.

  “Digestive acid,” Lena said over the comms, her voice breaking up with static. Her signal from the Field Deck was weak here. “The environment… is trying to… digest you.”

  “Great,” Jace grunted, wiping a smear of yellow slime from his visor. “We’re in the stomach. I hate the stomach.”

  “Movement,” Rina hissed.

  She froze, her bow drawn. She was aiming at a cluster of nerve-trees twenty yards away.

  At first, Alec saw nothing. Just the twitching of the gray fibers.

  Then, the fibers separated.

  A creature detached itself from the trunk. It had been camouflaged perfectly, its body mimicking the texture of the nerves.

  It was an arachnid, but wrong. It had eight legs that ended in surgical scalpels. Its body was a bulbous, translucent sac filled with blue electrical fluid. Its head was a cluster of sensory needles.

  [ENTITY: SYNAPSE STALKER]

  [LEVEL: 25 (ELITE)]

  [TYPE: AMBUSH PREDATOR]

  “Level 25,” Alec whispered. The blood drained from his face.

  On Earth, a Level 15 Null-Hulk was a boss. A Level 18 Void-Serpent was a catastrophe.

  Here, a random mob was Level 25.

  “Don’t engage unless it sees us,” Alec ordered quietly.

  The Stalker chittered—a sound like dial-up internet screeching through a bone saw. Its sensory needles twitched. It swiveled toward them.

  It saw them.


  “Contact!” Rina yelled. She loosed an arrow.

  The shaft flew true, aiming for the creature’s fluid sac.

  THUNK.

  The arrow hit the sac.

  It didn’t pierce. It bounced off.

  “Immune?” Rina gasped.

  “No,” Alec realized. “Damage reduction. The level gap is too high. Our gear isn’t punching through its natural armor.”

  The Stalker shrieked and leaped.

  It covered the twenty yards in a single bound, moving with terrifying speed.

  “Jace! Shield!” Alec shouted.

  Jace stepped forward, raising the Bastion Heavy Shield.

  The Stalker slammed into him.

  CLANG.

  The impact drove Jace back three feet. His boots gouged furrows in the muscle-floor. He grunted in pain as the force traveled through his injured torso, but he held the line.

  “It’s heavy!” Jace yelled, bracing his shoulder. “It hits like a truck!”

  The Stalker raised its scalpel legs and began to hammer on the shield. Clang-clang-clang. Sparks flew.

  “Flank it!” Alec ordered.

  He stepped out from the bone arch, ignoring the acid rain stinging his face. He raised his hand.

  “Essentia Bolt!”

  He poured mana into the spell. A violet lance of energy struck the Stalker in the head.

  The creature flinched, but it didn’t die. Its health bar barely moved.

  [DAMAGE RESISTED]

  “Magic resistance too?” Virgil yelled, firing his plasma rifle. The blue bolts scorched the creature’s carapace but failed to burn through.

  “It’s not resistance,” Alec shouted. “It’s the math! We’re under-leveled!”

  The Stalker turned its attention to Alec. It opened its mandibles and spat a glob of blue fluid.

  Alec dodged. The fluid hit the ground where he had been standing.

  Violet sparks erupted. The muscle-floor seized up, contracting violently.

  “Neurotoxin!” Eleanor warned. “Don’t let it touch you! It causes paralysis!”

  The Stalker ignored Jace and lunged for Alec.

  “Alec!” Rina screamed.

  Alec didn’t have time to cast a shield. He raised his axe.

  The Stalker’s scalpel-leg came down. Alec parried with the haft of the axe. The wood groaned. The creature was incredibly strong. It bore down on him, its needle-face inches from his own.

  He could smell the ozone on its breath.

  “Gravity Well!” Alec roared.

  He cast the spell point-blank, centered on the creature’s abdomen.

  The air warped. Gravity increased twenty-fold.

  The Stalker screeched as it was slammed into the ground. Its legs splayed out. The fluid sac on its back bulged under the pressure.

  “Hit it now!” Alec yelled, holding the spell. His mana bar drained rapidly.

  Rina switched arrows. She pulled a heavy, black arrow from her quiver—one of the Void-Tips they had looted from the Reapers.

  She drew to her cheek. She aimed not at the sac, but at the joint where the leg met the body.

  THWIP.

  The arrow struck. The void energy ate through the chitin.

  The leg sheared off.

  The Stalker thrashed, unbalanced.

  “Virgil! The eyes!”

  Virgil switched his rifle to overload. He fired a single, high-intensity beam directly into the sensory needle cluster.

  The creature’s head exploded in a shower of blue sparks.

  The Stalker went limp.

  Alec released the gravity spell and stumbled back, gasping.

  [TARGET ELIMINATED]

  [XP GAIN: 3,500]

  “Three thousand,” Virgil breathed, checking his interface. “That’s… that’s a lot.”

  “It almost killed us,” Rina said, her hands shaking slightly as she lowered her bow. “That was one mob. A trash mob. And it tanked a full party assault.”

  Alec looked at his mana bar. [MANA: 60%].

  He had burned nearly half his reserves on a single enemy.

  “We can’t fight our way up,” Alec said. “Not like this. If we pull a group of two or three of those… we’re dead.”

  Jace slumped against the bone arch, clutching his side. Eleanor was already at his side, casting a minor healing glow to soothe the bruising from the impact.

  “We’re not geared for this floor,” Jace rasped. “My shield took a durability hit. It’s dented.”

  “So we go back?” Virgil asked.

  “The gate is closed,” Alec said. “There is no back. There is only up.”

  He looked out at the jungle. The trees were twitching. He could hear more chittering in the distance. Dozens of them.

  “We need a strategy,” Alec said. “We can’t clear the floor. We don’t have the resources.”

  He looked at the ground again. At the scorched path Vane had left.

  Vane had an army. Vane had elites. Vane had plowed through this jungle like a bulldozer.

  “We draft,” Alec said.

  “Draft?” Rina asked.

  “Like a race car,” Alec said. “We get in his slipstream. Vane is ahead of us. He’s clearing the path. He’s triggering the spawns. He’s tripping the traps.”

  Alec pointed to the trail of destruction.

  “We follow his mess. We stay in the dead zone behind his army. If we see a mob, we hide. If we see a trap, we assume Vane already sprung it.”

  “We’re scavengers now?” Jace asked, grimacing.

  “We’re survivors,” Alec corrected. “We let the Warlord do the heavy lifting. We save our strength for the floors that matter.”

  “It’s risky,” Virgil noted. “If his rearguard catches us…”

  “Vane took his rearguard with him,” Alec said. “He thinks we’re dead or stuck in the lobby. He’s rushing to the top. He won’t be looking behind him.”

  Alec hefted his axe.

  “Let’s move. Stick to the burn marks.”

  They moved out.

  The jungle was a labyrinth of horror.

  They walked through groves of nerve-trees that shivered when they passed. They stepped over pools of digestive acid that bubbled and popped.

  But Alec’s theory held. Vane’s army had been thorough.

  Every hundred yards, they found the carcass of a Stalker or a Neuro-Tick—massive, bloated parasites that had been hacked to pieces or blasted by heavy magic.

  The path was a scar on the living floor.

  But it wasn’t just monsters they found.

  An hour into the trek, Rina signaled a stop.

  “Body,” she whispered.

  They gathered around a corpse lying half-submerged in a pool of acid.

  It wasn’t a monster. It was a human.

  He wore the black armor of an Ascendant Mercenary. One of the men Vance had hired.

  He hadn’t died in combat.

  His legs were broken. He had been thrown into the acid pool.

  Next to the pool was a withered, dead flower—a Sartorius Trap. A massive, carnivorous plant made of muscle. Its jaws were clamped shut, but it looked burned out, exhausted.

  “He triggered the trap,” Virgil said, scanning the scene.

  “No,” Alec said, looking at the angle of the broken legs. “He was thrown into the trap.”

  Jace swore softly. “Vane sacrificed him. The trap was blocking the path. Instead of fighting it or disarming it… Vane threw a man into it to make it snap shut.”

  “Efficiency,” Alec said, his voice cold. “Kaelen said Vane valued efficiency. Why waste mana fighting a plant when you have spare bodies?”

  “He’s burning his own army to climb faster,” Eleanor whispered, looking sick.

  “That’s why he brought so many,” Alec said. “They aren’t soldiers. They’re ammo.”

  Rina knelt by the dead mercenary. She reached into his belt pouch.

  “He has supplies,” Rina said. “Mana potion. Dried rations. And a datapad.”

  She handed the pad to Alec. The screen was cracked, but functional.

  It was a log.

  [USER: MERCENARY UNIT 89]

  [TIME: 0400 HOURS]

  [LOG: The Warlord is insane. We hit Floor 2 and the difficulty spiked. He’s not stopping to rest. He’s pushing the pace. We lost Unit 4 and 12 to the ticks. Then he ordered Unit 7 to walk into the acid mist to test the pH levels. We’re not an army anymore. We’re canaries in a coal mine.]

  “He’s terrified,” Alec said.