The end of the maintenance conduit wasn't a door.
A single rusted wire fence separated the researchers from the lower levels.
When Ria pulled out the mounting pin with a pair of pliers, the fence tilted outward. Hot steam and the smell of oil rushed in at once.
Aaron checked his wrist first.
05:31:42.
It had taken them more than twenty minutes to get out of the conduit.
The red dot was still moving west.
"It's picked up speed."
Ria looked beyond the fence.
"How much?"
"Faster than a person can walk. About the speed of a small transport cart."
"Then someone is moving it."
The two of them stepped down out of the conduit.
Velcarium's lower levels were less like the same city and more like a gigantic engine room supporting the upper and middle levels. Dozens of layers of bridges and pipes tangled overhead, and the vibrations of steam trains sifted dust down through the gaps.
No sunlight reached this far to mark the difference between day and night.
Instead, orange gas lamps and aether work lights illuminated the narrow alleys.
The sight was familiar to Aaron.
Back when he worked at a repair shop, he had to come down here to find cheap parts. Things the middle-level merchants had marked as scrap and passed off were repaired and reused another three times in the lower levels.
People weren't all that different.
"Do you know the way?"
Ria asked.
"I know as far as the Scrap Engine Aggregation District."
"What about inside?"
"I've never had clearance."
"You won't have it this time, either."
Aaron covered the blue mark on his wrist with his sleeve.
"I'm doing a lot without clearance today."
"You're adapting quickly for your first day."
Ria glanced back at M-03.
The automaton had been walking on its own since they came down from the conduit. Its movements were still unsteady, but it was faster than when Aaron had been carrying it.
"Status?"
M-03's glass eyes blinked once.
"External administrator signal weakened. Independent operation possible for one hour and thirty-two minutes."
"Does it stop after that?"
"Unpredictable."
Hearing the answer in Johan's voice made it even less reassuring.
Ria spoke quietly.
"We need to fix the power unit before we reach the aggregation district."
"We don't have time."
"If it stops in the middle, we'll have to carry it and run."
"I'll carry it."
"With your hands like that?"
Aaron looked down at his bandaged hands.
"You could carry it, Senior Researcher."
"I have to clear the way."
"With what?"
Ria pulled a short pistol from inside her coat.
It was an industrial impact gun fitted with pressure-regulating tubes around the barrel. It was used to shear equipment bolts or shove aside improperly fitted metal plates.
Against a person, it could serve another purpose well enough.
"Researchers carry things like that around?"
"You walk into exploding engines carrying cutting pliers."
"I suppose we have different approaches to our work."
Ria tucked the gun back inside her coat.
"Starting today, they'll be more alike."
It didn't sound like a promising forecast.
They crossed a narrow market alley.
The shift change must have been approaching, because people in work clothes were pouring out. Coal dust covered their faces and hands, and nobody welcomed the sight of white research coats.
At the first alley, Ria took off her coat and turned it inside out. The inner side was made of dark gray fabric, so from a distance it looked like an ordinary work jacket.
"It does that?"
"It's for investigations in the lower levels."
"Do you come down often from the institute?"
"When there's an accident."
"Before an accident?"
Ria didn't answer.
The missing part was the answer.
Aaron buttoned his own coat all the way up as well. He tucked his contract researcher ID deep into an inside pocket.
M-03 wrapped a piece of worn cloth around its head and shoulders. From a distance, it might pass for a small-framed laborer.
Up close, its metal joints were plainly visible.
"Can you walk a little more naturally?"
Aaron asked. M-03 looked at him.
"Requesting definition of naturalness."
"Like a person."
"Insufficient sample."
Ria started walking ahead of them.
"Just keep it in the middle. Around here, anyone who spends too long looking at someone else's business is more suspicious."
She was right.
The people of the lower levels glanced at M-03, then quickly looked away. A broken automaton mattered less than the wages they would be paid today and the homes they would return to that evening.
The red dot on Aaron's wrist began to wobble again.
It turned north instead of west.
"The target has changed course."
Ria scanned their surroundings.
"Is it avoiding us?"
"If it can sense that the mark is being tracked, that's possible."
M-03 spoke.
"External signal repeatedly selecting shielded zones."
"Is it moving intentionally?"
"Unable to determine."
Aaron matched the red dot on the map against the actual distance.
The target was moving along the outskirts of the Rusted Valley. Even though it could escape faster by going in a straight line, it was circling through the interior, where abandoned engines were densely packed.
It looked like it was hiding.
Or someone was hiding it while moving it.
"We need to take the western transport route."
Aaron pointed to the opposite end of the alley.
Ria looked that way and her expression hardened.
"There's a Calder checkpoint."
"If we go around, we'll be more than thirty minutes late."
"If we get stopped, we won't make it today."
"Is there no way through?"
Ria looked Aaron up and down.
"They'd let us through if you showed them your contract researcher ID."
"And the institute would receive our location at the same time."
"So would Calder."
Aaron looked at the numbers on his wrist.
05:17:09.
Time was running out.
"Then we'll make a route that isn't a checkpoint."
"How?"
Aaron looked up at the pipes overhead.
An old steam transport pipe ran alongside the transport route. Its pressure gauge hovered just below the yellow zone, and a maintenance ladder connected to the far side of the checkpoint.
"We'll go up there."
Ria looked back and forth between the pipe and Aaron's hands.
"With your hands like that?"
"I've heard that one already."
"Because they're in worse shape than before."
"If we go below, we'll be stopped."
Aaron checked the ladder's mounting bolts.
"If we go above, the only risk is falling."
"Don't say that like it's the better choice."
"It'll be over faster than being caught and interrogated."
Ria let out a short sigh.
"Your survival standards are strange."
"I'm still alive, so they must be working."
Aaron placed one foot on the ladder first.
When he gripped the metal rung with his bandaged hand, the burned area began to throb again. A cold pulse beat through the opposite wrist, where the mark had been implanted.
Ria steadied M-03 from below.
"If you drop it, your administrator privileges are over, too."
"Is that concern for me?"
"At least you'll scream if you fall."
M-03 lowered its head.
"Voice output possible in event of a fall."
Ria stared at the automaton for a moment.
"Johan never made jokes like that."
"Not a joke."
Aaron pressed his lips together to keep from laughing above them.
The top of the pipe was wider than he had expected.
It was barely wide enough for one adult to walk on, but sufficient for passing above the checkpoint. Below, guards in the gray uniforms of Calder Heavy Industries were stopping cargo trucks.
They opened the cargo beds of every vehicle and inspected the insides.
Aaron's gaze stopped at the third truck.
Blue light leaked out from beneath a black tarp.
The red dot on his wrist jolted violently.
A-08 external signal nearby.
The distance was only thirty meters.
"It's the truck below."
Aaron spoke quietly.
Ria lay flat against the edge of the pipe and looked down.
"It doesn't have a Calder mark."
"Then whose truck is it?"
"An unregistered recovery team."
As soon as she finished speaking, the man standing beside the truck looked up.
He stared directly at the pipe through black safety goggles.
It didn't seem as though their eyes met.
But the man raised a hand and waved twice.
The checkpoint guards all looked up at once.
"They've spotted us."
Ria drew the impact gun.
"They detected the mark."
Aaron's wrist grew hot.
The mark connected to the underground facility gave off heat for the first time.
A sentence appeared in his vision.
External administrator access attempt.
"Someone's trying to access the mark."
"Can you block it?"
"I don't know how."
M-03 grabbed Aaron's wrist.
A blue ring spun rapidly inside its glass eye.
"Administrator privilege conflict confirmed. Temporary shielding possible."
"At what cost?"
"Reduced operating time."
"How much?"
"Estimated one hour."
Aaron looked at the truck below.
A-08's signal was inside it.
If M-03 stopped, there was a strong chance he would lose Johan's records and negotiating authority. But if they seized the mark, they could take not only his location but also the terms of his agreement with the underground facility.
"Shield it."
Ria turned to Aaron.
"You decided fast."
"I need to leave myself time to regret it later."
M-03 pressed its fingers against the mark.
A cold shock surged up Aaron's arm.
The red dot in his vision blinked out for a moment.
At the same time, one of the automaton's eyes went dark.
"Temporary shielding complete. Remaining operating time: one hour and twenty-six minutes."
The benefit was clear.
Their opponent's access was cut off, and the map in Aaron's mind could no longer be seen from outside.
The cost was clear, too.
M-03 could stop before they even left the lower levels.
Gunfire rang out below.
The metal plate beside the pipe crumpled.
Ria grabbed Aaron's shoulder and ducked him down.
"Run."
"Where?"
"Onto the truck."
"The height—"
"You said falling ends faster than getting caught."
Having his own words thrown back at him, Aaron couldn't argue.
Ria fired the impact gun downward.
Compressed air and a metal slug struck the checkpoint's steam valve. The valve broke, and white steam blanketed the transport route.
The guards' vision was obscured.
Ria jumped down from the pipe first.
She landed on the cargo truck's tarp and dropped to one knee. Then she immediately turned and reached a hand toward Aaron.
"M-03 first!"
Aaron pushed the automaton down.
Ria caught it and laid it on the truck.
Aaron jumped after it.
The impact traveled up through his ankles and knees. He lost his balance and rolled across the tarp, but he didn't fall off.
"It's moving!"
Someone shouted below.
The truck lurched forward.
Aaron grabbed the tarp's tie-down rope. Blood seeped through the bandages.
Ria looked toward the cab.
"They're moving because they know we're aboard."
"Is that good?"
"Only the part about being on the same truck as the target."
"And the bad part?"
"The destination might not be where we want to go."
A bullet punched up through the tarp.
A black hole appeared between them.
Aaron rolled to the side.
M-03 shoved a hand through the torn opening.
"Internal structure confirmed."
"What is it?"
A brief burst of static mixed into the automaton's voice.
"Six aether preservation containers."
"Are there people?"
M-03 stopped.
Its one remaining eye turned toward Aaron.
"One biological response."
The red dot on Aaron's wrist lit up again.
This time, it wasn't on the map.
It was moving directly beneath his feet.
A-08 external signal match: ninety-seven percent.
Aaron pulled open the torn section of tarp.
Below, blue crystal containers were secured in rows.
A child was curled up inside the smallest container among them.
He couldn't see the child's face.
But a strip of old cloth was tied around the child's wrist.
A forgotten sensation came back to Aaron.
Nine years ago.
A smoke-filled corridor.
A small hand that had tried not to let go of his.
And the same strip of cloth.
The child slowly raised its head.
Their eyes met through the container.
The child's lips moved.
No sound reached him.
But Aaron could tell what the child was saying.
Don't come.
The very next moment, the mark on his wrist turned red.
A-08 contact confirmed.
Awaiting facility transmission.
Ria grabbed Aaron's arm.
"Stop the transmission."
"M-03 has to determine what the mark does."
They both turned toward the automaton.
M-03's remaining eye was going dark.
"Administrator privilege maintenance limit."
Johan's voice cut in and out.
"Aaron. Choose."
"Choose what?"
"Whether to tell the facility."
M-03's head slowly lowered.
"Or cut me off."
The automaton's eye went completely dark.
The truck picked up speed as it entered deeper into the Rusted Valley.
The transmission countdown on Aaron's wrist was ticking down.
00:00:29.