“Move back!” Skyler shouted at her.

She pressed herself against the sidewall instead.

He jumped as he reached the back of the personnel carrier, and turned and rolled as he did so. His legs flipped around and over him as he tumbled into the back of the vehicle, mud spraying from his boots.

Ana, unencumbered by any armor, leapt over him and reached out for the door handle.

A shape, a being, emerged from the gloom of the tunnel.

“Look out!” Skyler roared, fumbling for his pistol.

Ana didn’t miss a beat. She simply grabbed the door handle and yanked it with such ferocity that even she wasn’t prepared for how fast it swung. Her feet tangled with Skyler’s legs.

The armored subhuman in the tunnel jumped, hands outstretched and flaring with bright red light. It hit the door, adding its own weight and momentum to Ana’s pull. With a thunderous boom the heavy door slammed shut. Ana toppled over Skyler and hit the floor of the compartment, hard.

A second of silence passed. Then something pounded against the door, hard enough to rock the vehicle.

“Go,” Skyler said. “Go!”

He heard the whine of electricity surging through the vehicle’s four motors. The next sound filled him with fear. Wheels spinning uselessly in mud.

“Slowly, Vanessa,” he growled toward the front, where the woman sat hunched over the steering wheel. “Let it get some traction.”

Vanessa tried again, coaxing the accelerator this time. At first nothing happened, and then the wheels began to spin against the mud below again, gaining no purchase.

“It’s not working!” Vanessa shouted back.

“Fuck, fuck,” Skyler whispered.

Pablo’s Gatling gun thrummed to life again. Skyler heard cries of pain from somewhere outside and wished he had a window.

Vanessa, in frustration probably, slammed the accelerator to full power. She was only digging them in deeper, Skyler knew. He had to take the driver’s seat from her, and was starting to rise when the armored subhuman in the tunnel slammed into the vehicle again. Even through the closed rear hatch, Skyler could see the flash of reddish light flare in through the tiny gap around the edges. The whole APC lurched forward from whatever weapon the subhuman had embedded in its hands. Lurched enough that the tires found a bit of purchase. Vanessa still had her foot firmly planted on the accelerator, and like a caged animal being freed the vehicle surged into motion.

Skyler saw Pablo turn around, heard the Gatling begin to sing its deep song again.

“The trigger,” he said to Ana.

She nodded, went to the side bench, and picked up the small transmitter. It was a simple metal box, with a plastic bulge on the front that covered a tiny switch. Ana flipped the cover up and thumbed the switch.

On the drive into the circle of red aura towers, Ana had pushed bundles of explosives out of the vehicle every ten meters or so. Each had been fitted with a custom arming switch, cooked up by some of the techs in camp. The bombs would arm when they came in range of the trigger Ana now held. Once armed, when the trigger left their range the bombs would detonate.

Ana grinned mischievously when the first explosion went off, a grin that turned into a broad smile with the second, and third.

Skyler found himself smiling, too, until the APC hit a bump in the ground that sent him bouncing upward. His skull smacked into the ceiling, not hard, but enough to remind him of the danger they were still in.

“Take it easy up there!” he shouted forward to Vanessa.

“Bite me,” she shot back.

More jostling followed as the APC barreled over fallen trees and rain-carved grooves.

Explosions continued to go off in rhythm with their departure. Skyler had no idea if the bombs would kill, or even harm, a single subhuman, but the hope was that it would keep them from following. At least until the APC reached the road.

“Low on ammo!” Pablo shouted down from his perch on the turret.

“Conserve it until we’re back on the path,” Skyler said.

“Almost there,” Vanessa said over her shoulder. Then, “The towers are moving.”

“Just as we hoped,” Skyler said. “Get ahead of them if you can, and let Karl know to be ready.” He got to his knees on the floor of the compartment and studied the object he’d stolen from the cave. In shape it almost reminded him of a giant wedge of cheese, square on two sides and triangular on the others. Two points of the triangle were sharp, but the third, the “tip,” Skyler decided, looked as if it had been cleaved off. He wondered at the reason for that, but knowing the object would fit into a specific place inside the Builder ship seemed to answer the question: It would only fit in one position, like a puzzle piece. Or a key.

Skyler lifted it into a hard case, then closed and latched it.

Explosions trailed behind them, every two seconds.

“The armored one is following,” Pablo said. “The rest stayed inside the mist.”

Skyler glanced at Ana. “How far behind us is it?”

“Ten meters,” Pablo said. “I can’t get a good shot.”

Ana read Skyler’s face and knew his plan almost before he did. She moved to the rear and grasped the door’s handle.

Skyler lifted the seat of one bench, revealing a compartment within. He pulled another assault rifle and thumbed it to explosive rounds.

“Do it,” he said to Ana.

She yanked the handle and pushed the door open.

Skyler stared down a “road” of flattened trees and crumpled foliage. To his left and right, enormous aura towers lumbered along in the same direction the APC headed, knocking over everything in their path as they made their way back to the space elevator.

Off center, but on the path, a black-armored subhuman sprinted toward him. The creature moved with inhuman speed, augmented no doubt by the strange material that coated its entire body.

One of Ana’s bombs went off a few meters to its left, and the creature stumbled but hardly broke stride.

Skyler aimed, a pointless endeavor in the bouncing, jostling vehicle. He pulled the trigger anyway and held it down. The rifle chattered, followed a split second later by a myriad of small flashes around the feet of the creature. Some of the shots went high and exploded into the trees at the side of the carved road. Splinters of wood filled the air behind the subhuman like confetti.

Finally Skyler got the weapon under control and swung it back toward his target. A round exploded off a clump of dirt just beside the creature, and it dodged left.

A fatal mistake.

Just as it stepped one of Ana’s bombs went off, right beneath it. The subhuman cartwheeled into the air, limbs flopping with sickening lifelessness. It landed in a splash of mud, unmoving.

Ana hooted in victory and rattled off a string of words in Spanish that needed no translation.

Skyler kept the gun trained on the body until it faded from view. Two more of Ana’s bombs went off before they passed the point where she’d started to drop them on the way in.

Vanessa weaved the vehicle around a few more aura towers, and then they were clear. The towers were all behind them, making their slow journey back to camp. Skyler guessed it would take them half an hour to reach the base of the Belem Elevator. By contrast, the towers released when he’d picked up the object in Ireland were still weeks away.

He left the rear door open and set his weapon on the side bench. “Vanessa, let Karl know we’re en route, and to get everyone ready on those barricades.”

“Already done,” she said. “He said the cord shook a few minutes ago, like before.”

The second object we’ve picked up, but the third time that’s happened. He didn’t like what that implied.

The camp had drilled four times in the last two days for the possible return of the aura towers. Portions of the barricade around the camp had been placed on wheeled pallets, and the expected path to the center of camp had been cleared of structures, tents, and vehicles. No one wanted a repeat of the mess their departure had created.

Skyler leaned under the roof turret, squinting as he looked up. “Pablo, you all right up there?”

“Uh huh.”

“You can come down if you want.”

“I’ll stay. Just in case.”

“Suit yourself.”

A moment later Vanessa turned them hard left and gunned the motors. Teeth-rattling bumps turned into a gentle sway as the vehicle transitioned into the potholed road.

“Help me with this,” Skyler said to Ana. He tugged at the heavy armor on his chest and Ana stepped across the cabin to assist. Together they lifted the bulky plated mass over his head and dumped it on the floor with a deep, dull thud.

“That’s better,” he said, and leaned his head back against the wall. The rush and chaos of battle behind them, Skyler’s thoughts turned almost immediately back to Tania. The sacrifice she’d made so that he would have enough air to survive. The sight of her drawing that last tiny breath before her oxygen ran out.

He felt the sting of tears and willed them away. A familiar hollowness slithered into his gut, something he’d foolishly hoped would fade with the distraction of a mission.

Ana, uncanny in her ability to sense the shifts in his mood, took a seat next to him on the bench, folding her legs up beneath her and resting her head on his shoulder.

He took her hand in his, and together they watched the infinite blur of forest go by.

At Camp Exodus, Karl waved them in. He stood in the middle of a widening gap in the colony’s wall, a bullhorn in one hand and a radio in the other. Colonists scurried about, pushing portions of the wall aside. Farther inside camp, more people worked to reposition the temporary structures that surrounded the base of the space elevator. A few forklifts assisted the effort, tracks coated brown with mud.

Rain pounded the entire area. It had been relentless for the last week, turning the unpaved areas of camp into muddy ponds and the rest into slippery patches if one wasn’t careful.

Vanessa pulled to a stop next to Karl and they exchanged a few words. She coaxed the vehicle forward and turned hard left, moving them toward the river, well out of the path of the incoming towers.

Skyler could see almost nothing but a rain-lashed windshield; still, he knew the camp’s layout like the back of his hand and could guess how far they’d driven. “That’s good enough, Vanessa. Park here; we’ll help them prep.”

She obliged, rolled to a stop, and killed the current to the motors.

“Damn this rain,” Skyler said once he set food outside. The thick drops of water fell in an almost artificially steady pace. He left his body armor in the back of the APC, and offered Ana a hand down to the ground. She jumped instead, wincing slightly on the landing and probably hoping Skyler hadn’t noticed. He pretended not to and pulled his bushman’s hat from the pocket on his pants where he kept it. The downpour soaked the treated leather before he could get it on his head. “This is miserable.”

Ana pulled her own hat on, a black baseball-style cap unadorned with any logo. She still wore her shorts and tee, but at least she’d pulled a combat vest on over the thin top. She flashed him a thumbs-up.

“Pablo, Vanessa, guard the … thing,” he called out, and they set out.

They met Karl at the edge of camp. He stood on a scaffold that had been bolted to part of the wall there, allowing a kind of lookout. A metal ladder provided access, and Skyler climbed up. Ana, he noted, stayed behind. The lingering pain in her back must be flaring up again, but he knew better than to suggest she find somewhere to lie down.

Karl held a set of binoculars to his eyes. He lowered them as he made room for Skyler. “Can’t see shit in this rain. Are half coming?”

“Just like Ireland.”

“Okay.” He turned and raised his bullhorn. “Control team, into positions!”

A portion of the camp had been cleared in a pie-slice section expanding out from the Elevator base, in the direction of the crashed ship out in the rainforest, plus a healthy buffer around the entirety of the disk that marked the cord’s actual connection point.

“Think it’s enough?” Skyler asked.

“Only one way to find out.” Karl waved as a group of colonists emerged from the shelter of a camper some distance away. They rushed forward and swarmed into the cleared space.

Skyler noted that the rest of the colonists had also sprung into action at the command Karl had shouted, retreating far to the opposite side of camp by the university complex.

The “control team” fanned out and spaced themselves evenly in a line, halfway between Aura’s Edge and the base of the Elevator.

Karl spun around and scanned the forest again. The path originally carved when the towers had left was still detectable if one knew where to look, but a remarkable amount of foliage had already regrown along the route.

Skyler heard the towers before Karl saw them. The crack of young trees being folded in half, the crunch of rock being pushed aside. Muted under the heavy rain, but there, and growing louder.

“I see them,” Karl said.

Visibility in the rain was two hundred meters at best, one hundred at worst. What Skyler expected to see was tall, black towers pushing through the wall of rainforest that ran right up to the edge of Belem’s slums. Instead he saw the foliage begin to whip and sway, as if a strong wind had suddenly rose.

Then the towers came.

Like an advancing army of siege engines from medieval times, the dark obelisks powered their way through the tree line. Skyler’s heart leapt when those at the vanguard suddenly dropped as if falling into a pit, until he realized they were just crossing the steeply banked water channel that marked the border where city and rainforest met. The towers rose again a half second later as they reached the other side, a fine mist of water rising from where their bases touched the swollen waterway.