That had been her second mistake.
Her uncontrolled lunge smacked her into the bottom of the tunnel, then she fell. The HUD was blaring in her ears, and the LEDs within the helmet were flashing red. While she was flailing, the HUD activated an emergency override, taking control of the suit.
The left mount launched one more explosive, lowering the timed duration until detonation. Not a second later, an eruption of energies sounded from below, creating a vicious updraft that slowed the suit's fall long enough to dig the knuckles into the nearest rock wall.
Before, they would've torn through like sand falling through a sieve. But with the slower descent, the suit's power could pierce the rock with just the right amount of pressure and at just the right angle to recover from any further lost height.
Gina looked down, thunder alive in her chest. She couldn't see anything below, the all-consuming darkness swallowing up the suit's headlights. She considered dropping a flash cylinder and letting her suit grab a few post-flash images of the surrounding terrain below, but that was quickly dismissed. In the near-darkness, she was already at a disadvantage against the Aud. If she used a strong light source, she'd be trading vision for safety. It'd be a beacon in the dark. Plus, in the excitement of the fall, she'd remembered she used the last on the purple Aud.
"Can I climb back up?" She prompted the HUD after deliberation.
"Declaration: Current rock wall is connected to same decaying tunnel above. Inference: Corrosion of rock and mineral composition holding structures in place spread to current position. Rejection: Implementation of proposed plan leads to failure to retain current height and safety parameters."
It fell silent, fueling Pa-5's frustration. What was she supposed to do, hang here until a lucky Aud discovered her? Before she could inquire again, the HUD forwarded its own plan. "Alternate proposition: Continue in vertical descent. Observation: Corrosion of rock structure's integrity lessens further down.
The suit dedicated more power from the core to its vision, strengthening the night vision function. Once it reached an optics setting she could see the rock wall comfortably with, the HUD activated the new path, highlighting a series of handholds and footholds that could support the WAV's weight.
Pa-5 adjusted her position, climbing through the only space she could access. The rock wall crumbled through, and she lodged her feet deeper. Waiting until the shifting grew less unstable, she moved to the next position. It contorted her leg awkwardly, but she withstood the discomfort. It hurt less than her ribs.
She was making good progress when she noticed movement in her periphery. She froze. Not a second later, the HUD confirmed her suspicions. "Observation: Green fur detected sixteen meters to right. Recommendation: Remain still. Upon discovery, utilize explosive to distract."
And then what? Jump down the rest of the way and hope the impact didn't crush her inside the WAV like an egg? There was anti-grav padding on the inside, keeping her body centered and preventing it from leaning too much on any particular portion of the insides without worrying about impacts. But it had limits. It would only protect her to a certain threshold, and after that, she could only toss up her hat and hope for the best.
In the seconds before she was discovered, she went through her inventory. She had two explosive orbs left. Like all WAVs, her suit was also equipped with a pairing blade in each wrist and sonics mounted within the shoulders, but she had no reason to use them until now. She was still running a retreat, not a guerilla campaign.
She gave the portions of the rock wall the Aud was ripping to shreds as it climbed a second look. "HUD?"
It told her what she wanted to hear. Although that segment was far enough from the corrosion to remain more stable than hers, it was close enough that it was still more fragile than normal. With a strained smile, her right shoulder twisted in its socket, bringing the sonic implanted within to bear on the Aud.
The sonics line of defensive weaponry employed by the First Ray were among the most powerful they could arm their pilots with. Even the modules slotted into light WAVs could stagger a blue Aud. In a perfect world, that would be enough to bring them down.
But this wasn't a perfect world. Not by a long shot. At best, they'd stay disoriented just long enough for a second or consecutive shot from another supporting pilot. All by her lonesome, Pa-5 would only get a single shot off before a whirlwind of death was upon her
But there was one thing many pilots often forgot: to stagger an Aud at all, sonics were extremely powerful. It was just that the Aud was even more so, which made the weaponry humanity relied upon to continue carving an existence for itself weak and faulty in a direct comparison.
So she wouldn't aim to attack the Aud itself. It wouldn't fall if she did that, and it would reveal her location. Sonics were loud, even if they emitted no muzzle flashes. But what about its perch?
The mount shifted, bringing its aim lower until it had a clear lock-on to the rock wall beneath the Aud's belly. She sucked in a breath. Felt the tension build in her chest. Held it until she was ready to burst, watching the Aud crawl closer, completely unaware of the prey lying in wait only a few meters away. Released the breath, and felt the burn be cooled. And fired.
The Aud had been detaching a hooked claw from the stone when the sonic round hit, smashing the rocks in front of it into a million tiny pieces. From the impact site, a dozen cracks spidered out, running up and down the wall in every direction with a blitzing fury.
The Aud growled, its eyes already tracing the line of the round to its source. Her blood ran cold when it caught her in the darkness. But it was too late to do anything. Before it could leap at her to take her head off, its limbs were broken free from their supporting holds.
Only its front legs remained buried in the stone, but it was breaking away faster and faster; the weight of an Aud was too great. Gravity dragged it further down, no matter how much it struggled to climb back up to her. Rather, each movement only worsened the situation, until it was at the edge of her optics. With mad murder in its eyes, it captivated her gaze until it disappeared into the darkness.
She stared after it, then began moving again, ignoring the tremors of her body and trusting the WAV's servos to keep her decline controlled. She had a few hours at best before it climbed back up, and she needed to be long gone by then.
The climb was faster than it had been before. The HUD, just as aware of the time bomb ticking above its pilot's head, rerouted the path again. Several points had vanished along the climb, and the remaining ones were risky to grab. It was emphasizing speed and efficiency of movement at the cost of safety.
After the two-kilometer mark, she had to find a perch to rest at. Although the WAV did most of the heavy lifting with the assistance of its servos and movement sensors, she still had to act as a model for the suit to sync its actions. Which meant every time she grasped, it grasped. Every time it reached for footholds, she painfully stretched her body to make it happen.
The HUD located a small alcove carved into the side of the wall. It was an artificial construction, between where she'd found it and how abnormally smooth it was on the inside. At a different time, she would've held suspicion against its mere existence, but as she let the WAV come to a sitting position, she was grateful it was there. Curiosity was for another time and another person
In the alcove, she panted into the darkness. She could hear in the passing echoes both the sounds of the cave drafts and the Aud somewhere below and around her. She was sure more were moving along the walls; she had yet to meet them. Light was even more dangerous now that she had already signaled her approximate location once with the sonic round.
Absent-mindedly scraping the WAV's knuckles across the ground, she frowned when they raised and lowered in a pattern. Although the suit core was becoming rather low, she could spare some power. Her night vision flared to life again, and the darkness dissipated up to the mouth of the alcove. Looking around, she smiled to herself in pleasant surprise. The first smile since she'd left Fort Io. Those events felt like a lifetime ago.
She was in the center of a spiraling carving, with waves moving up and down in a loose hyperbolic display. Those were what she was feeling. It was arrayed into a nonagon. At each corner was a triangle raised from the surface. She winced, seeing one of the triangles crushed. She had stumbled over something when she first entered, dismissing it as a rock.
She looked at the other triangles, changing her mind. All but one were smashed similarly, torn apart with a relentless stabbing motion she recognized as an Aud's signature stomp. Why spare one? No, better question, why damage the stone carvings in the first place?
She tried to glean what information she could from the damaged triangles, but whichever Aud had gone to town, it'd done a good job. She couldn't even guess the original heights of the triangles. The HUD informed her that this feature of the greater tunnel wasn't newly made.
And she agreed. Although the alcove was ridiculously smooth, almost to an impossible degree, it still showed the occasional crack here and there. It couldn't have been older than a century, though. That just made no sense.
Sighing, she crouched by the final stone triangle. Although she could have extracted and taken it, it struck her as disrespectful. She couldn't put her finger on why. Her hand hesitated.
This one was a hand. It had what looked like moss growing over the skin, and it was cupping water. This water pooled over the edge of the fingers, reached the bottom of the triangle, and vanished. Aside from the moss, the hand was particular in how it was made. There were eight fingers and two thumbs instead of the traditional five-fingered hand. It made for an odd sight. She wanted to scrutinize the rest of the floor carving.
But more than that, despite knowing she should sheath it away, her curiosity was an unbridled beast that was as hard to cage as an Aud.
Over three centuries occupying the Gaiss Hollow encouraged humanity to explore and change the local features several times. More than once an exploration survey had found some form of shrine or rock carving further along in the greater tunnels. They'd marked the artifacts, cataloged them as best they could, and moved on.
But this segment of the Greater Western Tunnel Systems had been traversed dozens of times. She supposed that something this high up was likely to be missed, but consecutively? Back to back? She doubted it.
The Aud had. They weren't held back by the same vertical constraints humans were; they had unlimited freedom in every manner except flight itself. A fine case study was when hundreds climbed up the Gaiss Hollow's ceiling and dropped down on Fort Io. She winced at the memories.
And how the other triangular…what? Symbols? Talismans? Representations? The other triangles had been decimated in a fashion that all but screamed intent. And intent required intelligence.
Her blood ran cold. Intelligence? No, that couldn't be right. Surely this had been a simple case of a careless Aud making a resting place decades ago and ruining the art.
But why were the triangles the only obviously broken part? Why wasn't the rest of the stone carving a fractured, alien mess? Her hand, still waiting, finally reached down and seized the base. Yanking, she ripped the last surviving triangle free and deposited it in another compartment.
She was shaking, unsure which idea scared her more as she stared off into the darkness. That the Aud had advanced enough mental faculties to understand what vandalism was? Or that this intelligence, no matter what degree it'd grown or changed, had eluded the attention of the One-Light Directory throughout a centuries-long war? The HUD injected another cocktail to lower her stress levels.
But when the HUD informed her of light tremors thirty meters over, it was time to move, to stuff away these new concerns in the back of her burdened mind. Her joints still suffered as the climb down resumed, but her muscles had stopped transmitting signals like they were on fire.
The grasp of the WAV was just as strong as ever. It combined her coordination and guidance with its raw strength to claw a way onward, leaping and jumping from hold to hold on the HUD's path with incredible finesse for its size. The optic sensors not facing her front were working overtime, their implanted mounts running back and forth, back and forth, in a desperate competition with her movement sensors to catch an Aud first.
She was through the fifth kilometer--and still nowhere near the halfway mark, when the HUD blared a warning. Without explanation, she could feel her WAV growing heavier. Much, much heavier. Before she could blink, she was falling. This time, the suit couldn't stop the backwards descent.
And that was her third mistake. She never maintained a watch over the charges of the external anti-grav modules.