The corridors made more sense after a full day inside Iron City.
Not because they were mapped but because they were patterned.
Marcus noticed it during movement hour. Every shift, every door opening, every pause between alarms followed rhythm. The city didn't run on schedules. It ran on pressure. Push too slow, and you missed access windows. Push too fast, and you drew attention.
Both were dangerous.
He followed the flow of bodies into the lower tiers, the air growing warmer and thicker with sweat and oil. Sound finally existed down here metal clanging, breath hitting concrete, the low murmur of voices that never rose above a certain level.
This was the underground.
Not hidden. Tolerated.
A wide space opened below, carved out of reinforced rock. Rings, cages, training pits, and makeshift bleachers stacked along the walls. Screens hovered overhead, tracking strikes, endurance, reaction times. No scores shared out loud. Everyone already knew where they stood.
A man with a crooked nose and one blind eye leaned against a railing beside Marcus. "First timer?"
Marcus didn't answer.
The man chuckled softly. "That's a yes."
"Rules?" Marcus asked.
"Yeah," the man said. "Rule one don't fight fair. Rule two don't fight angry. Rule three don't fight for the crowd."
Marcus glanced at the stands. "Who am I fighting for, then?"
"Your ranking," the man replied. He tapped the symbol on Marcus's collar. "And whatever they promise you next."
A bell rang sharp, electric. The pit lit up.
Pairs moved in, one after another. No introductions. No names. Just motion. One man went down wrong, shoulder folding inward with a sound Marcus felt in his teeth. No medic ran in. Two escorts dragged him away.
"Limited support means exactly that," the blind-eyed man said. "Live, you heal. Lose, you're recycled."
"Recycled how?"
The man shrugged. "Depends which department needs bodies."
Marcus's match flashed on a screen.
UNDERGROUND TRIAL
OBJECTIVE: ENDURANCE
TIME: UNKNOWN
He stepped into the pit.
His opponent was taller, broader, calm in a way that came from experience not ego. Eastern posture. Centered weight. Controlled breathing.
"First rule," the man murmured, bowing his head slightly. "Control the mind."
Then he attacked.
The fight was slower than the arena upstairs, heavier. Each strike carried intent. Marcus adapted, shifting angles, breaking rhythm. Pain traveled up his arm as a counter landed clean.
Endurance. Not victory.
Minutes stretched. Sweat burned his eyes. Breath came harder. The city watched always watching.
At some point, Marcus realized the truth.
The underground wasn't about skill.
It was about how much of yourself you were willing to spend.
His opponent staggered first. Marcus didn't press the attack. He waited. Let fatigue speak louder than fists.
Finally, the bell rang.
Both men stood. Neither fell.
TRIAL RESULT: PASS
ATTRIBUTES UPDATED
The opponent bowed again. "You learn fast."
As Marcus stepped out, the blind-eyed man grinned. "You didn't try to kill him."
"I didn't need to."
"Good," the man said. "Killers burn out. Survivors climb."
A runner approached Marcus and wordlessly handed him a ration chip higher tier than before.
More reward. Deeper leash.
That night, sleep didn't come easy.
Noise crept into his dreams crowds screaming without faces, battles repeating themselves with different uniforms, different weapons, same outcomes.
When he woke, a message pulsed on the wall.
UNDERGROUND CLEARANCE GRANTED
NEXT PHASE UNLOCKED
Below it, smaller text scrolled.
IRON CITY HAS RULES.
LEARN THEM OR BECOME ONE.
Marcus sat up, muscles aching, mind sharp.
Somewhere in Iron City, his brother had learned these rules already.
The question wasn't whether Marcus could survive them.
It was what they would cost.