“I thought you’d want to see this,” Kurt said. “After all, you got us into this with your ‘Crow and Pitcher’ idea. Seems appropriate that you’re here for the final answer.”
They reached the inner door. Two Chinese technicians were already there. Deposited by one of their own submersibles. One of them had thick glasses and hair that hung in his eyes.
Kurt cocked his head. “Didn’t I see you on Hashima Island?”
The man nodded. “I was in the metallurgy lab.”
Kurt nodded. “Still haven’t found a barbershop, I see. What are you doing here?”
“They released me to help with this investigation,” the technician said. “I know more about this place than most. I helped design the systems.”
“Many of which are still functioning,” Kurt said. “You obviously do good work.”
“The power is nuclear. The reactor was untouched. When the avalanche occurred, the watertight doors sealed the interior. That’s the only reason.”
Kurt had a feeling there were other reasons. He kept it to himself. “Ready?”
“Yes.”
Opening a side panel, the engineer accessed a manual release for the inner door. Using a large wrench, he turned a spindle and released the latch.
Kurt and Paul pulled the heavy door open. They discovered a tunnel, bored out of the rock and sheathed in steel. Lights running along the top remained lit.
“We need to see the main section,” Kurt said.
“This way,” the technician said, leading them into the tunnel.
The first passageway led to a second and then to a staging area, where stacks of equipment sat undisturbed.
They crossed the staging area and arrived at a huge freight elevator—two cars could have fit in it side by side. “Do you hear something?” Paul asked. “A low hum?”
Kurt nodded. Clue number two. He climbed onto the elevator and waved for the others to join him. “Going down.”
They took the elevator down nearly a thousand feet and arrived at a different section of the mine. On the schematic, it was listed as “Lower Control Room.” It was only supposed to be four hundred square feet, a twenty-by-twenty space. But it proved to be a vast, open cavern. Dark tunnels could be seen all around them.
“It’s like Grand Central Station,” Paul said.
Kurt nodded, looking around. Power cables ran everywhere. Fresh tank tracks marked the ground like a construction site. The humming was louder.
The two engineers crossed the room to a control console. Paul and Kurt wandered in the other direction. The steel walls they’d found earlier had given way to an amber-hued mix of rock and Golden Adamant.
“None of this should be here,” the engineer said. “This is only supposed to be a drop-off connecting the control room to the deep boreholes. This entire room . . .”
His voice trailed off as a rumbling sound became audible. All of them turned to see a bank of lights approaching from one of the tunnels. A crawling machine lumbered into the cavern and then maneuvered to a spot by the wall. Its front end appeared to be damaged. It parked and then used a robotic arm to grab a power cable from the wall that it plugged into its battery pack.
Clue number three. “All of this is here, because the machines built it for themselves,” Kurt said.
“What?”
“They’re still digging,” Kurt said. “Following their orders. Using their artificial intelligence program to determine the best way to accomplish their goal.”
As Kurt spoke, the engineer from Hashima Island brought up a schematic of the mine on the console. It displayed hundreds of tunnels and rooms that had been drilled and excavated in the last year. They’d pushed the harmonic resonators deeper into the Earth than anyone believed possible, overcoming problems and setbacks. Using the minerals and alloys they recovered to buttress the mine in many places.
“How did you know all this?” Paul asked.
“I didn’t,” Kurt said. “But Hiram Yaeger and Priya reviewed all the data that Han’s people had recorded. They came up with this as the most likely explanation. There was no other way to explain the continued and accelerating fracturing of the transition zone down below. The machines had to be digging. Expanding the operation as fast as they could.”
As Kurt spoke, two other machines appeared. One of them went to work on the damaged hauler and began repairing its front end. The second machine crossed the cavern and entered a different tunnel, off to some new task.