The tentative plan to drive the cart another two hundred miles to the England-France dome proved ridiculous.  Even discounting the limited range of its battery and the spares rattling in its small bed, it was decades old, it didn’t move any faster than a brisk jog, and its motor badly needed greasing.  Some joints in its exposed chassis only held together because they had rusted that way.
Moreover, the maps Grid had copied weren't current.  They marked rough ground, sunken and flooded passages, and cave-ins, but not all of those.  They discovered that when they had to return up a half mile of tunnel upon finding that it unexpectedly dove into a salty pool of unknown depth and breadth.  At another point, they had to lift the cart over a cave-in that left just enough room to get it past the damaged ceiling.
“I think this isn’t working,” Valle said, when the low-battery light began to blink on the console.
“This is the only way,” Grid muttered.  “Keep an eye on the charging light.  We could pass through the edge of a charge field from the subway or something.”
She’d said that before, and so far Valle hadn’t noticed that light coming on, in all the sixty-some miles they’d gone.  The bat reached over from where he lay in the back seat and pressed his palm against the power switch.  Grid tried to swat his hand away, but he was braced against the seat firmly enough to resist her.  The cart skidded and stopped.
“Come on,” Grid complained.
“I’m gonna test the batteries.”
Swapping the batteries meant disassembling part of the undercarriage (while seated on the damp floor), which was why they’d been reluctant to try it earlier.  Grid stood by glumly, holding onto bolts and caps for Valle as he worked.  The effort showed that both spare batteries had about a third of a charge.  They connected the cart’s computer to her tablet to map out how far that could get them.
Assuming no more obstacles that didn’t show on the maps, their three batteries could just barely take them to a tunnel beneath the next dome nearest Osah’s.  They might be able to walk the rest, if they were up to attempting their rescue then after a long walk and more than a day without food.
“We have to at least find another deeptown,” Valle said.
Grid groaned, and then cursed.  She stood and shouted wordlessly into the pitch-dark distance.  When she was done she sat down and threw her head back, with an unsettling crack from her mechanical neck.
“Then what?” she sighed after a few moments.  “Maybe someone can charge us, we get the cart running, it takes us three times as long as we think it will because the map’s shit and the deepways are more shit, we get there and find there’s no way up, like the way we got down here in the first place, and we have to turn back.”
“We could go in aboveground and be spotted immediately.”
Grid turned her yellow eyes at him sharply, but huffed and looked down at the cart’s floor.
“At the start, I thought it was about fifty-fifty that when I grabbed you, you’d tear me in half then and there.  Then it turned out that you’re probably the single best person to have with me on this.  And everything could’ve gone to shit a hundred times, but it didn’t.  Then in half a second, I threw away the only ally we had.  And Ding was just a kid.”
“He had a gun on me.  I don’t have any problem with him being dead.”
“Well, they did nab the two of you for a reason, even if you didn’t turn out as bad as Crucis.”
Valle blinked at the sting of that.  He got back into the back of the cart and sat opposite her.
“That’s fair,” he allowed.
“I could’ve aimed lower.  Or used the butt.  But I killed him, and I completely failed my wife.”
She met his eyes, and then buried her face in her hands.  Her fingers dug deep into her dirty feathers.  Valle nodded, though she couldn’t see, and put a tentative hand on her knee.
“I blew it,” Grid said weakly.  “They’ll call me a traitor now, and I might as well have thrown Marn straight into Osah’s lap.”
She hugged her shoulders and shivered.  Valle didn’t think it would help to say anything, except, after a minute:
“Trade seats.”
Grid obliged, gave him the wheel and her tablet, while she sank into the floorboard of the rear.
***
Reaching the nearest town marked on her maps took several hours, and put them far out of their way.  It used up the first battery and ran the second down to its dregs.  The town was smaller than the one they had left in the night, an old, permanent settlement of stone and brick homes clustered near the walls of its chamber.  That might have been dug to be a fresh water reservoir centuries ago, or a drainage basin.  Its ceiling was too high to see from the floor, even with bright gas lamps on posts every few yards.  There were several other vehicles parked around it, shabby and handmade like theirs, and a single goat in a pen.
The town was built around a natural gas vent that opened in the floor and seemed to be permanently burning.  For the moment, Valle was liberated from his blood money, which meant that Grid had to dig through her pockets for small change to buy them a cooked meal at the flame.  An old, sour-faced human man bundled in several layers of coats and scarves cooked it for them without a word.  He was offended when Grid didn’t eat, but still silent.
Valle stood to look for anyone he could ask for help (he discounted the cook).  He made a full circuit of the town’s few footpaths without receiving more than a shrug from anyone he asked.
Compared to the rest of the deepways, this chamber was much more comfortably dry, if little warmer.  The stone houses, roofed with mats of compressed paper, were like those in photographs of quaint antediluvian cottages.  Goat and all.  None of that made the populace much more welcoming, though.
Finally someone approached him.  A human child, wiry but made round by a bulky coat, stopped in front of him and studied him with candid wariness.
“The men in my dad’s house wants you to come,” she said, and turned to lead him without a response.
All Valle could do was follow.  The girl took him to a house near the edge of the town and pointed into its doorless entryway.  Inside, warming his hands over a heated stove, was Kierghan.
“Hey!” the resistance fighter called after Valle, when he backed away from the door.
Two others Valle had seen in the encampment waited outside.  One was the corvine zoan.  Valle scowled and raised his hands.
The resistance men didn’t have to ask where Grid was, the flame being only a minute’s walk from anywhere in the town.  When Kierghan called her name, she jumped out of her seat and stumbled away - but the human held out a hand in peace.
He unloaded a canvas sack from his shoulder and offered it to her.  Inside was an extra battery and a bundle of sandwiches.
“Lorian says Ding was out of line,” Kierghan gestured to the crow.
Grid looked between them tensely.
“Is he okay?” she asked.
The scarred face tried to stay neutral, but was weighed down.
“We’re down a man,” he said.
“I’m sorry.”
“Not everyone believes Lorian, but enough did that they let me come for you.”
“What, a trial?”
Kierghan scoffed through a slight smile.  “No?  To help get you in.”
Valle relaxed for the first time, while Grid stared, disbelieving.
“But you have to be honest with us,” Kierghan looked to the bat.
***
That was a hurdle, but Valle had nothing to tell but the truth.  It certainly didn’t clear him of suspicion - Lorien the crow’s glare showed that well enough - but it also confounded any reasons they could think for a Veritas operative to follow Grid like he did.  A full accounting of his movements since he had abandoned Atlantis, and hers since setting out - including details she hadn’t yet revealed to Valle before, such as the weeks she spent working with a circle of watchdogs who tried to track Crucis - put the fighters more at ease.  Enough, at least, that they ceased to brace for the bat to try and slaughter them all at any moment.
They were able to recharge their batteries overnight, by suitcase-sized generator the town kept powered by the gas line.  In the morning, they rode out in three carts, in one of which was loaded the painter’s scaffold and spider drone Kierghan had brought to the factory.
The drive was slow and difficult.  Even the more complete maps the revolutionaries had couldn’t account for every obstacle, every new flood.  But they were able, taking a winding route, to reach the deepways running beneath the England-France dome, with plenty of power for the return journey.
Grid was quiet the entire way, eyes downcast. Valle didn’t try to make her talk.  
When they came near the tunnel that could have connected directly to the buildings adjacent to Osah’s, the pounding of a security drone’s heavy gait sounded like the fists of a giant knocking against the concrete from below.  Valle, who had seen his share of those beasts in his youth, hushedly urged the little caravan to back up and get out of this tunnel as quickly as possible.  The monstrosity would tear them to pieces from farther away than they could see it, if they let it detect them.
“At least we know we have the right place,” Kierghan whispered, once they were safely back across the threshold into the previous shaft.  He was too jovial for this business.
They reviewed their maps, and found another set of passages that seemed to have exits leading into the substructure below a block not far from the Osah complex.  Valle could find those buildings in Dresden’s model, and though he couldn’t get floor plans, it was enough to fill in their prospective route.
The other passages weren’t unprotected, but the smaller drones that patrolled them had gone feral, and wouldn’t be reporting what they saw until a technician came in person to reinitialize their software. They only scuttled in the dank, communicating silently with one another and avoiding the wheels of the vehicles that passed through.  It seemed to be a good existence, all told.
The opening to the sublevels of the buildings above was a dark hole in the ceiling, a stream of ocean water ran down its side to create a curtain of droplets and rivulets along the floor.  The revolutionaries unloaded, and Kierghan sent the spider drone to inspect the shaft and hang the pulleys if it was secure.  The buglike machine lowered itself back down a few minutes later, reporting all clear.
All five rode the painter’s platform up.  They left their firearms below in case their ammunition could trigger chemical detectors, but still had knives and one springgun.  Lorian, the crow, had a rugged tablet, with which he monitored the security of the building they entered.  It would be useless against anything Osah had.
With combat-trained precision, with which Valle was more than capable of following along, they stalked the sublevels, cutting through the office complex’s boilers and HVAC and plumbing nodes to avoid the dark hallways where they might encounter its maintenance staff.  They disabled the emergency exit and took a stairwell up to the lowest rooftop, onto which they emerged in complete shadow.  The air was stuffy and unpleasantly warm after several days in the deepways.
They could see it from here, revealed by lights along its walls that shone down on the road far below.  The squat and unassuming but severe headquarters of the Oversight and Sanctions Administration.  It had been nearly twenty years since Valle had seen it, and the sight made him churn inwardly.  The many smaller buildings that comprised the complex clustered around the central block like supplicants reaching to touch a savior.  Any information they were going to find would be in that one, as well as Valle’s home for six years.
The revolutionaries helped him and Grid move between roof tops, with a zipline and grapple where needed.  Until, with the headquarters a scant few hundred yards away, Kierghan stopped them.
“This is all I can do,” he said.  “I don’t think I’ll get permission to help you back.”
Grid accepted that with a shallow nod.
“You should expect,” the human continued.  “for the resistance to consider you an enemy after this point.  I don’t know if that’ll be the case, I hope it’s not, but you need to be prepared.”
The hawk closed her eyes.  Not looking, she offered Kierghan her hand to shake.  He tried to make it a hearty embrace, but she shrugged out of it.
“Thanks,” she said softly.
“I know you’ll get her.”
Kierghan lingered, long enough to nod to Valle as well, before signaling for the others to withdraw.  The three of them started the long journey back to the deepways opening, immediately swallowed up by the shadows of the office buildings.
Left with a harpoon gun for the zipline, a springgun, a spare tablet, and a final paper-wrapped meal, Valle and Grid stood alone with Osah in their sights.