“I think I know the place you mean,” Saskia said. “Very close to the German border. The neighbors would complain about the noise.”
T.R. nodded. “The Greens would lose their fucking minds.”
“They will anyway,” Bob said.
The lift slowed as it approached 215 meters below ground level. Their view was improving as, it seemed, some of the routed systems got routed elsewhere. It was now possible to see the six steel barrels of the gun arrayed around them. The lift eased to a stop. Through a window in its door they could see into a well-lit chamber beyond. It wasn’t a large space but it was definitely external to the main shaft. “See, down here at the bottom we did a little more blasting and hollowed out some extra volume,” T.R. said. He opened the door and led them into the side shaft. It was not much larger than the bedroom Saskia had slept in last night on the train. The walls were bare limestone, still bearing the marks of the pneumatic tools that had carved them out. The floor was a grate through which they could look straight down into another story below. No wonder she’d been warned not to wear heels. Two men and a woman stood against the back wall wearing air tanks on their backs connected to respirator masks dangling free on their chests. “Safety first!” T.R. said, waving at them. “This area has plumbing for four different gases, three of which can kill you. One, natural gas—basically methane, which we get for free from a well right here on the ranch, about ten miles away. That is the fuel we burn to power the gun. Two, air, which we use to burn the methane and which, incidentally, keeps us alive. Three, hydrogen, which is the light gas we compress to drive the projectiles up the barrels. The air in the peashooter. We obtain it by cracking natural gas in a plant upstairs. Either hydrogen or methane would cause an explosion if it were to mix with air, as the result of a leak or malfunction, and be ignited by a spark. So, four: as a backup system we have stored down here a large quantity of compressed argon, which is an inert gas that does not support combustion. Or life. Now, to be clear, the methane and hydrogen lines have been totally disconnected. We’re not stupid. There’s no way such a leak could happen right now. If one were to occur, it would be detected by these here doohickeys.” He indicated a white box mounted to the stone ceiling that looked like a smoke detector as designed by the Pentagon. Saskia now noticed more of them all over the place, merrily blinking. “If that were to happen, an alarm would sound and argon gas would flood this whole volume and drive out the air and render the atmosphere non-combustible.”
“And then we would all suffocate,” Saskia said.
“Good news, bad news!” T.R. confirmed. “That’s why we have portable air supplies. Each of these fine people is wearing one and has a second one handy. If the alarm sounds, they’ll do what it always says to do in those goddamned pre-flight announcements.”
“Got it,” Bob said. “So, if we hear a loud noise, we should wait for one of them to get after us with an air tank.”
“You shouldn’t have to wait long,” T.R. assured them, “and the argon won’t hurt you while you’re waiting. It’s—”
“An element,” Saskia said.
“Bingo. An inert gas. A noble gas, Your Majesty. There will be plenty of time to ride the elevator to the top, where we will serve drinks.”
“Sounds like my kind of emergency!” Bob said—a joke at his own expense.
“Any questions? Good. Having gotten the safety briefing out of the way, I propose to show you how the Biggest Gun in the World works from the bottom up, as this is the easiest way to understand it. And we are not quite at the bottom yet. This is Level Zero. I am told you both feel comfortable with ladders. Let’s put that to the test by descending to Level Minus One and beyond.”
A ladder was bolted to the stone wall, descending through a human-diameter hole in the grating. T.R. waited as one of the safety crew climbed down it, then followed with a certain amount of comical slapstick grunting and groaning intended to put them at ease. “Keep going!” he said to everyone. “’Til you cain’t go no more!”
Saskia and Bob took turns with the other crew members in descending to Level Minus One, then Minus Two, and so forth. At each level Saskia looked out at what was in the adjoining shaft, but after Minus One there was nothing to see except a blank wall of steel, curved to fit perfectly in the shaft. “The cylinder,” T.R. said at one point, noting her curiosity.
Minus Four sported a massive round hatch, a meter in diameter, let into the wall of that cylinder. Minus Five had nothing but routed systems of the smaller and more intricate type: sensors, probably networked to computers elsewhere. At Minus Six, the ladder stopped and they bottomed out on a natural limestone floor. “This is the base of the excavation,” T.R. said. “This is all the farther we dug. And this here”—he rapped a knuckle against the cylinder wall—“is the base of the cylinder, where the methane burns.”
Another round hatch was let into the steel wall here, and it was ajar, with an extension cord running into it from an outlet on the wall. T.R., with help from a crew member, shoved on the hatch, which was slow to get moving but then glided serenely. It opened inward. Saskia could see that it was designed to withstand internal pressure, like a bung on a barrel. The space beyond was illuminated well, if harshly, by an ordinary work light plugged into the extension cord. T.R. bent over and stepped through, beckoning Saskia to follow.
“The wall is so thick!” she exclaimed as she was stepping over the threshold. “To withstand pressure?”
“Ain’t really as thick as it looks,” T.R. demurred. “It’s got a cooling jacket all around it, coupla inches thick, but hollow—we pump water through it to keep it from overheating when it is bang, bang, banging away.”
“That would explain the cooling tower I noticed topside,” Bob said.
“Yep, and a lot of pipes and pumps along the way.”
They were now in a steel-walled chamber about five meters in diameter. Its floor was concave, a flattened dome, so they had to mind their footing. Below the level of the port, at about knee height, it was ringed with an array of stainless-steel orifices. Other than that the walls were featureless to a height of about four meters above their heads, where a sturdy steel ring had been welded into place, projecting just a few centimeters inward from the wall. Directly above that was a flattish dome that completely sealed off the portion of the cylinder above it. “That thing moves. You’re looking at the underside of the piston,” T.R. explained. “Down here, where we are, is where we explode shit.” He bent down and tapped one of the orifices. “These are coaxial. They let in compressed methane and compressed air at the same time. They let it in fast to keep reload time to a minimum. When we get the amount we want, we plug our ears and spark it off with these.” He pointed out a tiny detail Saskia hadn’t noticed before: little white ceramic knobs between the nozzles, with tiny metal parts projecting from the ends. “Plain old ordinary spark plugs from the car parts department at T.R. Mick’s. Volume discount.”
There wasn’t much else to say. They took turns stooping down and exiting the port. T.R., the last one out, carried the work light with him and pulled the extension cord out in his wake. The crew members pulled the hatch shut and latched it while others ascended the ladder to Minus Four, where earlier they’d seen another port-and-hatch. Entering into this one—which was just the upper portion of the same cylinder—they found themselves again on sloped footing, as they were now standing on the top of the domed piston whose underside they’d been gazing up at a few minutes ago.