Stuffing the last explosives in a shoulder bag, Durwood heard a whimper. The boxcart was packed and ready. Ten flights down, dressed up like a croissant cart. Anyone peeked under that tarp, though, they wouldn't find donuts and coffee. He needed to get rolling.

He zipped the bag and heard another whimper.

"Nope." He started for the fire escape. "No room in the cart, girl."

Sue-Ann stood in the center of the hotel room. Those amber eyes sagging.

"Y'be fine," Durwood said. "Rest those hips."

The dog scrabbled forward a step. That back-left leg hitched, and her face crunched up. The trip overseas had been hard.

"Well," he said.

She urged toward him, hopeful.

Durwood rubbed the base of his neck. If he rejiggered the frag grenades at the bottom, she might fit. Just. Wouldn't be a pleasure cruise.

"Alright," he said. "I'll carry you."

Sue-Ann hadn't done stairs in years, and he could not risk boarding an elevator with all the explosives slung over his shoulder.

Durwood controlled his breaths under the strain of the dog and bag. He hated to reward a beg, but he hadn't liked the idea of leaving her either.

This mission had a great chance of failure. Sue-Ann was old, and unlikely to take a new master. Might be better this way.

They reached street level. Parisian kids were poking around the boxcart. Durwood lowered the dog gently and shooed off the kids. Ducked through the tarp.

He knew the configuration of items by feel. Swiftly he added the charges and made Sue a space. Hoisted her inside.

She yipped when her haunch knocked against a rifle scope.

"Sorry there," he said. "Gonna be rough going."

He had double-cased anything combustible. The frags, the breach charges, full loadouts for the shot, sniper, and assault guns. Few other goodies.

The entry point he'd chosen was on Rue Leclair, six blocks up. Durwood released the wheel brake and pushed. A man in a chartreuse coat asked him for something. He kept his head down, kept pushing.

The entrance to Rivard's tunnel system looked like a regular subway vent. Wide grate, steam wisping up. He bent till the knees of his bluejeans touched the heavy-gauge metal. Looked down into pure black.

He took a crowbar from the boxcart. Sue-Ann, curled in a corner, raised an eyelid.

He said, "'Bout ready to take a ride?"

Durwood waited for a lull in traffic. Then spun out a half-dozen bolts and pried up the grate. Lowered a pair of two-by-fours into the void until they stopped with a thunk.

Each board had a magnet drilled into its end. He leaned hard to be sure they'd anchored well to the rails below. Then pulled the boxcart around and eased its treads onto the boards, lowering it down the makeshift ramp.

The boxcart grooved nicely onto Rivard's track below. He twisted on a microlight in his belt. Where the grate was coarse and weathered, made to look old, the track was gleaming steel.

Durwood shoved the boards back aboveground, abandoning them, and replaced the grate. He took a seat on top of the weaponry and reached forward for the pull-cord.

The boxcart felt steady underneath. Durwood had given her firm axles and minimal suspension. Three sides were built of walnut and the fourth brown maple, all reclaimed from street furniture. He'd teased out the grains with fine sandpaper, foolishly. Odds were this contraption would end up a pile of splinters.

He yanked the cord. The pinions caught, and the old Bendix drive began chugging.

He tracked their position on a handheld GPS device. The precise layout of Rivard's tunnel system was unknown. Whether it was a grid, hub and spoke. American Dynamics didn't know. Jim Steed had given him what maps and coordinates they had. The Anarchy had crippled shipping routes—lose half your cargo to thieves—and the tunnels allowed Rivard to get its products to stores and factories safely.

It figured this Leclair track led back to Roche Rivard, somehow or other. Did it pass through checkpoints? Were the cars that rode it controlled autonomously so a lone vehicle like his—dumb, unconnected—was at risk of crashing?

Durwood didn't know.

He had walked the tunnels a bit, done scouting trips. Not nearly the number he would've liked. Tunnel construction had already pushed their operation right up against AmDye's planned attack on the inner shaft. Luke Skywalker flying into the Death Star.

Steed said it could come any day. Today, even.

The boxcart moved west. Dank air whistled by, rippling Durwood's hat. Pebbles glanced off his face. The cart's engine ran quiet—for gas, anyhow—and zipped along decently. Every ten-odd yards, a purple LED tube gave off just enough light to suggest the tunnel's sides.

The tunnel sides were close. Sixteen, eighteen inches from the boxcart either way.

The cool temperature was ideal for a variety of shipments. Durwood detected the hum of various electronics behind the rock. These tunnels weren't built slapdash. Not in six months, or even a year. They'd been planned for a while.

Durwood worked a throttle and handbrake. Slower through turns, but harder into the straightaways. Quaid—or Claude, or Jesse, whoever he was at this moment—could only talk his way so far. At some point, he'd need what Durwood had in the cart.

Firepower.

Ten minutes along, Sue-Ann sat up. Durwood hear her fingernails on the boxcart floor.

"Sue? What do you have?"

Her mottled nose twitched. Now Durwood felt it, too. A slight pressure behind his eyes. The air different, sharper. Compressed. He became aware of moisture on his neck.

A light came into view. Just a pinprick but growing. With it came a faint hissing. Like the bacon Maybelle used to sizzle them up Saturday mornings.

The light got bigger. A headlight.

As the noise became thunderous and the lead car resolved, Durwood saw it was—like the boxcart—nearly as wide as the tunnel itself.

There were turnouts, recesses every so often where you could get off the main track. The last one had been a minute or two back.

Should I head back for it? Or go forward and hope to catch the next one?

He hit the throttle.

The oncoming car bellowed towards them. Bigger. Hissing louder, angrier. Durwood felt sure it was unmanned and would thoughtlessly slam them to kingdom come.

The wind pinned his ears as they accelerated. Sue-Ann mewed—high, pitiful sounds.

At the last moment, a break in the rock wall appeared. Durwood forced his boot down through the ammunition and charges, finding the rudder petal, squeezing the handbrake hard as he dared.

The cart rapidly decelerated and veered into the turnout. Rubber catches in the track stopped them altogether, smelling like an inferno in the Michelin factory. Durwood slammed forward into a crate of C4 cartridges.

The train rushed by, deafening, Durwood feeling like some raccoon was digging through his shirt to his innards. Displaced air rattled guns and grenades. Durwood's hip was pinned painfully against the far side of the boxcart. The noise dopplered ten seconds past the turnout, after the train's butt-end had disappeared.

Durwood shut his eyes.

It became routine, pulling aside every few minutes. Each train had its own unique sound. One shorter train gave off an urgent zing—a-zing-a-zing. Another came up behind them with a low grumble that put Durwood in mind of pigs at their slop—if you can imagine some real hungry, determined hogs.

After this last turnout, Durwood checked GPS. They'd been moving a while and the rock seemed changed. More porous. More fully muting the sounds of the Bendix engine.

The GPS beacon put him smack underneath Roche Rivard.

Their slope had been downward, Durwood felt confident. How down, though? How low had they gone?

According to schematics provided by AmDye spies, there were four possible chambers in this latitude-longitude range. Three were not good.

The topmost area was marked "experimental nanoblade." Durwood tapped into a note and read that Rivard was developing blades one atom thick, capable of slicing O2 molecules into two single oxygens. This was presumed to be military tech, since "any single oxygen that didn't react with its mate would immediately react with the nasal passages of anyone who breathed, causing severe burns or asphyxiation."

The next level down held a growhouse of carnivorous plants. Fabienne Rivard had given a TED talk predicting ore-based weaponry would be history within three-hundred years, and this research was thought to be her answer. Man-eating plants with constricting chutes and leeching tendrils and enzymes that could melt skin. The AmDye notes speculated the area would be recognizable by humidity and a low, green light.

Below the growhouse was the hyperdark chamber. Intel was scant here. "Characterized by extreme lack of light, owing to unknown (subatomic?) forces. Future applications: Unknown. Survivability: Unknown." Night-vision goggles were useless—there was ambient light to enhance.

The last possibility was the oubliette.

Durwood leaned an elbow into the turnout wall, head propped. His forearm muscles quivered from the work of steering the boxcart.

Sue-Ann sat up.

They could keep moving, follow the track to wherever it spilled out. Durwood had hoped exit would be possible straight from the rock, underground, but no. Most likely the track spiraled up to street level.

Where there would be sentries. Scanners.

"What do you say, ole' girl?"

He knuckled the rock. How thick were these walls? Three foot? Four?

He reached into the cart for Sue-Ann, lifting her, setting her on the track side of the boxcart. The boxcart would shield her some.

Next he removed a charge from the cart. Frame charge, four inches wide. He'd used such weapons to breach militant hideouts in Iraq.

He squinted at the limestone.

That sucker rebar-reinforced?

He put back the frame charge, took out a demolition charge instead. Good foot across.

He took out a second.

Using silver duct tape, he attached both charges to the wall at waist weight. Any higher risked a cave-in. Much lower, and the floor would sap the explosion of its full force.

He wired six feet of det-cord to the charge, draping it around the cart and squatting by Sue. Under less dire circumstances, Durwood enjoyed explosives. As a boy, he'd watched the coal outfits blast chunks out of the West Virginia mountainside. Set off his own firecrackers to coincide with their big ones.

Later, in the army, it had fascinated him that a little bridgewire and powder thrown together could wreak such havoc. He learned anything he could. When to use a granular versus a gelatin charge. Right length fuses. How you went about predicting projectiles.

No matter how far his skill progressed, his fascination stayed. His awe for the big boom.

He struck a match. Pffft.

The det-cord became a hissing snake of orange. Ash marched up the charge, dropping a fine dust to the limestone floor.

The hiss ran to the end of the det-cord, then stopped for a thick quarter-second. The sinews of Sue-Ann's neck stuck out.

Then:

GOOOOOMMM.

The concussive impact hit Durwood like two tons of water. The boxcart, thrown off its track, pinned his knees and boots. Watermelon-size chunks were falling all around, and a terrible ring spiraled through his ears.

He yanked free of the cart and looked over top. The wall was no more. A giant crater started three-quarters of the way up, taking much of the ceiling too. The rubble below stacked up nicely like stairs.

Durwood outfitted himself with shot and assault guns, an ammo vest, electostatic monitor. Few other doodads.

As he climbed into the bowels of Roche Rivard, exact point of entry unknown, Durwood heard nothing but ringing.

Did I blow my eardrums?

He would need his hearing for this fight. His hearing, and plenty more.

He punched out a last shard of limestone and stepped spryly through, Sue-Ann at his heel. The light was low and green. His skin felt creepy-crawly and the base of his throat furry.

His ears continued to ring. He snapped thumb and forefinger hard, right against the side of his head—and heard it.

So it wasn't his eardrums: it was the alarm.