Okay, here's a more human-sounding rewrite of the text you provided:
The Iron Fortress wasn't just stone; it was chained to a deadbeat schedule. Each door squeaked the same way, shifts changed with the exact same shuffle on the floor, and everyone's steps matched – men who hated anything different. This crazy discipline was the Purists' strength and Veridian's only shot.
For a whole day, Veridian studied her prison. She acted beat and went along with everything. She even turned down the gross soup the guard gave her, knowing they'd see it as being weak, not defiant. She figured they wouldn't push her to eat since forcing it would mean messing with their precious schedule.
Her cell, way down in the Outer Keep, cut her off from everything. It was dark as heck, but at least she had the clock.
Guard Shifts: Loud boots, the light rattle of the pike chain, and the scrape of the door locking shut – like clockwork, every six hours.
Water: The drips and pauses as someone filled a trough down the hall – twice a day, always between the second and third hour of the morning shift.
Patrols: One guard had a weird scrape to his boot, different from the rest. He passed her door every 90 minutes. This guy, the odd one out, was her first crack in the wall.
Veridian was good at reading people. The Guild built their system with perfect math, but the Syndicate stayed alive by playing on people's weaknesses. The Sentinels were stiff, but being stiff makes you easy to break.
The Glitch
Veridian watched the patrol with the limp. The faint drag on his left boot—probably from an old injury or something—meant he was hurting. He'd be slower, tired faster, and looking for any chance to chill. He was the weak spot.
She had to see the Fortress. She needed to figure out how far it was to the Cold Stone—where they were killing Elara—and find something with a ton of power to bust through the Chamber's anti-magic shield.
When the third shift change came, Veridian made her play. As the guards did their little handover thing outside her door, Veridian started moaning softly, then coughed like she was choking. She made it sound like her body was just failing, not like she was trying to get attention.
The guards stopped, a tiny break from their routine.
The limping guard (she called him Splayfoot in her head) sounded annoyed. The Syndicate's cracking. Tell the infirmary about her next round.
No, Veridian whispered, sounding weak. She was playing on the Purists' hate for sick people and their thing about being clean. Not infirmary. Fever. I'll get everyone sick.
The Sentinels hated germs. Sickness was a sign of being soft, something they wanted to wipe out. The thought of a fever messed up their perfect system was way scarier than someone trying to escape.
The new guard, thinking about keeping things from getting infected, agreed. Take her, Splayfoot. Get her to the Washing Stones. Clean her up, then bring her back.
A Quick Look Around
It was quick and awful. Veridian was chained up, her hands cuffed, and Splayfoot half-dragged her down the hall.
It hurt like crazy, but Veridian took note of every turn and slope.
Corridor: Long slope down. That meant the Outer Keep was high up, and places like the Cold Stone would be underground.
Light: She caught a glimpse of a main hall lit by oil lamps. Not fancy, but reliable. The hall split into three ways: Up (Barracks), Straight (Command/Mess Hall), and a shielded Iron Door (Storage/Engine Block).
Smell: Past the barracks, the stone smelled like oil and iron. That was the Engine Block and the Smelting Forge—the power source for the whole place.
Veridian's mind was racing. The Cold Stone needed to be cold to work. That meant power. Elara's prison had to be close to the power source she needed to steal.
Splayfoot dragged her to the Washing Stones—a freezing room where seawater poured over rocks.
Wash the filth off, Splayfoot ordered, unlocking one cuff and shoving Veridian toward the water. He watched the hall, worried about getting caught.
This was it. The slip-up.
The Iron Key
Veridian dunked her head underwater. It was so cold she couldn't see, but it hid what she was doing. She pretended to spasm, stumbling and slamming her chained wrist against the rough stone.
Help! she choked, acting terrified. The cold! I can't move!
Splayfoot jumped, surprised. His hammer was leaning against the doorway – he trusted it more than her.
Shut up, he growled, reaching for her, distracted.
Veridian played along. She grabbed the chain linking her cuff to the wall and yanked it free. The wall cracked, leaving a sharp piece of rock.
She now had a short iron chain and a sharp rock—her first weapons.
Splayfoot realized what was up way too late. He went for her, but Veridian swung the chain low, tripping him. He crashed to the floor.
Veridian didn't waste time trying to kill him. Too loud. She needed a quiet way out.
She grabbed the hammer. It was heavy and solid. She used it to smash the chain against the wall, loosening the pin in her cuff.
This isn't violence, Veridian whispered, her breath cold. This is taking what I need.
She ripped a piece of cloth from her tunic and stuffed it in Splayfoot's mouth. Then, she picked the lock on his belt with a piece of metal.
She grabbed a tinder box, a knife, and, most importantly, a key. This was the key to the Outer Keep's locks.
She left Splayfoot tied up, a glitch in the system. She put the hammer back by the door, a warning.
Underground Mission
Veridian slipped back into the dark hall. The patrol was coming. She had less than two minutes before someone noticed Splayfoot was missing.
She moved like a shadow. She reached the main hall and followed the smell of oil and iron to the Engine Block.
She used the key to quietly open the door. Inside, the loud machines covered any noise she made.
She was in the heart of the fortress. It was hot and smelled like oil.
She saw her men: Garth, Lys, and Kael, covered in grime, hauling coal and iron. They looked dead inside, moving like robots.
Veridian stuck to the shadows. She had to find the Cold Stone entrance and talk to one of her men without them breaking their vow of silence.
The only way to tell them her plan was to do something that made her intentions clear.
Veridian watched Garth working near the furnace. She knew what she had to do, and it would be loud. Her plan depended on her engineer understanding improvisation and structural failure.
She was going to wreck the machine that held them captive, right in front of the guy who hated her for being sacrificed.