Pointing at one glowing limb, Holden said, “Can you make that brighter?”
In answer, all of the glowing sections of the robot intensified until the tunnel was as bright as noon. The reason for the material transfer cart’s stoppage became apparent. A couple dozen meters ahead, the metal tunnel was blown apart and filled with rocks and debris.
Reading his mind, Miller said, “Yeah. Not everything is handling the reboot well. Power node for the mag-lev woke up bad and blew itself up. Only it’s not exactly mag-lev. Close enough, though, you can get the picture.”
“Can we get past it?”
“Well, we can’t repair the track, but I can get you out. Making passages,” the Miller-bot said, waving one massive claw in the air, “is what this thing’s for. He used to dig and maintain these tunnels. Hop on.”
“You’re fucking kidding me.”
“No, seriously, climb on. This guy can move faster than you can on foot.”
“Miller,” Holden said. “You are made entirely out of cutting edges and pinch points.”
One of the black tentacles twisted around, looking over the robot’s carapace carefully. “Hold on,” Miller said, and with a hum and a few metallic clanks, the torso of the robot twisted into a new configuration, leaving a wide flat spot on its back. “There you go.”
Holden hesitated for a moment, then climbed up one of the robot’s legs and onto its back. The Miller-bot trundled forward to the damaged section of tunnel and the four big forward limbs went to work, tearing out the twisted metal of the tunnel walls and clearing the earth and stone that had filled the space. The machine worked with speed, precision, and a terrifying casual strength.
“Hey Miller,” Holden said, watching the robot peel up a two-meter section of the tunnel’s metal flooring and rapidly cut it into tiny pieces. “We’re still friends, right?”
“What? Ah, I see. When I’m a ghost, you yell at me, tell me to get lost, say you’ll find a way to kill me. Now I’m wearing the shell of an invincible wrecking machine and you want to be buddies again?”
“Yeah, pretty much,” Holden replied.
“Nah, we’re good.”
He punctuated the words with one last massive blow that shattered a two-ton boulder into rubble. By hunching down on his six legs, Miller was able to squeeze through a small opening in the tunnel blockage. Holden lay down flat on the robot’s back, a jagged piece of the tunnel roof passing less than three centimeters from his face.
“Clear sailing from here,” Miller said, “but the mag-lev’s dead after this. No more trains.”
“We have any better idea what we’re looking for?”
“Only in general terms. About the time one-celled organisms on Earth were starting to think about maybe trying photosynthesis, something turned this whole damned planet off. Took it off the grid, and killed everything high enough up the food chain to have an opinion. If I’m right, the thing that did that’s not entirely gone. Every time something reaches into this one particular place, it dies.”
“Sorry to hear that,” Holden said.
“Don’t be,” Miller said. “It’s what we’re hoping for. Now buckle up. We’re going to try and make up some lost time.”
The robot bolted off down the tunnel, its six legs a blur of motion. Even moving at fairly high speed, the ride on its back was very smooth.
Holden surprised himself by falling asleep again.
He woke to something cold and rubbery touching his cheek.
“Stop it,” he said, waving one arm at the thing.
“Wake up,” Miller said, the detective’s voice rumbling though the robot’s carapace.
“Shit,” Holden said, sitting up suddenly and wiping saliva off the side of his face. “I’d forgotten I was here.”
“Yeah, I’d say a week of no sleep and too many amphetamines broke you a little,” Miller said. “You went on quite the bender.”
“Only without the fun.”
“I’ve been on a few myself,” Miller said and added a strange metallic laugh. “None of them are fun. But we’re about to hit the processing station, so get awake.”
“What should we be expecting?”
“I’ll tell you when I see it,” Miller said.
Holden pulled out his pistol and checked the magazine and chamber. It was ready to go. It felt a little like playing grown-up. Anything that the Miller-bot monstrosity couldn’t handle wasn’t going to be stopped by a few shots from his sidearm. But, like so many things in life, when you come to the spot where you’re supposed to do the rituals, you do them. Holden slid the pistol back into its holster but kept one hand on it.
It took him a minute to see it, but a point of light appeared ahead in the tunnel and then grew. Not reflected light from the robot, but something glowing. Holden felt a rush of relief. He’d traveled longer and farther than he knew in the small metal tunnels of the transfer system. He was ready to go outside.
The tunnel ended in a complex maze of new passages. A routing station, Holden guessed, where the arriving material was sent off to its various destinations. The walls were all of the same dull alloy as the tunnel. What machinery was visible in the cramped space was inset into the walls and flush with them.
The Miller-bot paused for a moment, its tentacles waving at the tunnel choices. Holden could picture Miller standing still at the junction, tapping one finger on his chin while he decided which path to take. And then, suddenly, he actually could see Miller overlapping the robot. The headache returned with a vengeance.
“That one was kind of your fault,” Miller said. “It’s an interactive system.”
“Do we have any idea where we’re going?”
Miller answered by trundling off down one of the many new tunnels. A few seconds later, they’d exited into a cavernous new space. It took Holden a few moments to realize that it was all still artificial. The room they entered felt too big to be a construct. It was like standing at the core of the world and looking up for the crust.
All around stood vast silent machines. Some were moving, twitching. They were recognizably designs that the protomolecule favored. They had the same half-mechanism, half-organic look of everything else he’d seen them build. Here, a massive system of tubes and pistons rising from a gantry twisting into whorls like a nautilus shell. There, an appendage coming from the ceiling, half again as long as the Rocinante, and ending in a nine-fingered manipulating hand the size of Miller’s robot. Light poured into the space seemingly from everywhere at once, giving the air a gentle golden hue. The ground was vibrating. Holden could feel the soft pulses through the robot’s shell.
“We’re in a lot of trouble, aren’t we?” Holden asked, breathless.
“Nah,” Miller said, rotating the robot to test the air in every direction with its tentacles. “This is just initial material sorting and reclamation. Not even to the processing center.”
“You could park a battleship in this room.”
“It’s not for show,” Miller said, then the robot began scuttling toward a distant wall. “This is the point of this planet.”
“Huh,” Holden said. He found he was missing all of his other words. “Huh.”
“Yeah. So, as far I can figure it, there are minerals native to this system that are fairly rare, galactically speaking.”
“Lithium.”
“That’s one,” Miller agreed. “This planet is a gas station. Process the ore, refine it, send it down to the power plants, then beam the collected energy out.”
“To where?”
“To wherever. There are lots of worlds like this one, and they all fed the grid. Not the rings, though. I still don’t know how they powered those.”
The robot moved with machine speed toward a distant wall, and a section of the structure slid away. It left an opening the size of a repair shuttle, and more lighted machinery beyond. Some of the giant devices were moving with articulations more biological than mechanical. They pulsed, contracted, rippled. Nothing so prosaic and common as a gear or a wheel in sight.