"All personnel, we're bound for the greater western tunnels. Prepare for higher output from the anti-grav generators. I'm raising modus operandi from yellow to blue. All pilots report to the front-facing garage for a possible sortie." Ze-4 angled the mic away.

  Their procedures encompassed thousands of variables per category. That the system's inventor had tied everything around something familiar saved him headaches. Many of the servicemen were new to serving on board Titans. He wouldn't've held it against them much if they couldn't remember everything without needing to consult their HUDs.

  Aud colors had remained a mystery, science-wise. The few scientists he'd had the patience to consult had more unanswered questions than he did. They'd pelt him with them if given any chance to open up on the passion topic.

  Like he'd know the answers when they didn't. Were they a chemical pigmentation based on diet? No, Aud exclusively consumed other Aud corpses and humans. Something the Aud could change at will, like camouflage plumage? If that was it, they'd better be grateful even the purples seemed a cartridge shy of a full magazine.

  He didn't entertain what the war would look like if the greens and above disguised themselves en masse amongst the low tiers. That kind of thought exercise was one of the last things he needed.

  In the absence of something better, most defaulted to treating the colors as markers for the danger a single Aud posed.

  White, for example, assumed the Nyx Breaker operated in friendly territory. At least one extra Titan also needed to be around. White didn't have many restrictions placed upon a Titan's crew.

  It was easy to get swept up by all the minute-by-minute changes. Being isolated in the command center didn't shield him from the whirlwind of activity enough. He mused on old memories from his compulsory service after Clyvis. He'd once been one of those soldiers running around below.

  Now, he was the higher authority that watched from above, the one he used to feel nervous about. Wondering if his superior was watching. Studying. Scrutinizing. Picking him apart.

  He added a few extra orders.

  "Engineering crews, allot more power through the energy grid to the echo room. Standard generators need to be on full output from here on until we're back in the Hollow. The Nyx Breaker's shielding generators might not perform to par. We'll overload them if we have to. Treat it as a variant procedure of modus operandi brown."

  The Nyx Breaker's first foray into the tunnels had mixed success and failure. When Re-5 asked him what function of the Titan he wanted to start testing on, he didn't know what she was talking about.

  "We're not only on a scouting assignment, remember? Or, now, I guess a location and extraction assignment?"

  Ze-4 looked down at his fingers. They traced the edge of the console. He didn't forget about the requested tests for as many of the Titan's finished parts as they could manage. The "test run" part of why they were out here. He was just thinking about more important things. Stuff he knew. What he didn't. What he wanted to know.

  He waved her away. "I trust you can cover that side of things?"

  Her eyebrows shot up. On second thought, that might've been too much responsibility to toss on an inexperienced aide. She wrestled her giddy smile under control and looked like she wanted to salute. One of his glares was enough to make her think otherwise.

  "I understand, sir, and'll get right to it."

  When she turned her back to him, he let his harsh frown lines relax. His head should stay focused on the assignment and his responsibilities. He was capable of doing that. Getting promoted to sitesman proved that.

  The Titan's crew received a list of every last relevant design feature and choice. Under Re-5, individual groups left their stations to tamper and prod at them one by one. While not all entries in the list were up to par, they did their jobs well enough. The Titan never suffered catastrophic failures in those initial hours. They didn't fall victim to the Aud.

  Hatches opened in the roofs of every compartment from the outside. The piloting crews couldn't get around the latest group of Aud without one of them getting too close.

  To compensate, sonics and electrics rained down on any Aud brave enough to try, which was all of them. The emplacements made up the difference there. Not all the Aud could survive attacks from dozens of turrets at once.

  Ze-4's fingers drifted around the console while he waited for new orders to give. One entry on the test list had stood out to him when skimming through it out of idle curiosity. Could the Nyx Breaker power its energy-hungry automated weapons systems and the echo room at the same time? Without one, they were toothless. The other left them searching blind.

  The answer was yes so far. If anything, the engineers had done too well with the generators. So much energy passed through the Titan's energy grid that components in the frame were melting. Several connecting wirelines were, too.

  Re-5 nipped the problem in the bud before he could comment on it. She assigned some engineers to moderate the output of several generators. Most of the energy going to tertiary or quaternary functions got cut back.

  The long, undulating body wove around itself as it moved along the walls. Ze-4 watched live feeds displaying the terrain ahead. Now and then, the Titan's pilots would hit a wall or accidentally steer down a sudden drop. Massive potholes.

  The Nyx Breaker had a design prioritizing speed and tight turn control. It was so fast and responsive that its pilots barely had seconds to react to oncoming obstacles. They hit something strong enough that a tremor went through the command compartment.

  He winced. Something heavy and dense got rammed if they felt that through the inertial dampening effect of the anti-grav generators.

  The Nyx Breaker's eyes were beacons in the dark. They'd attract Aud if they saw them. He made a call to one of the techs. Their profile image appeared in the corner of his HUD. "Why do we have spotlights announcing our presence turned on?"

  "They're necessary, sir. I'm not all that familiar with them, but I know they do something in tandem with the echo room's SWOD capabilities."

  "We're not turning them off?"

  "If you're concerned about attracting attention to ourselves, sir, we are in a massive metal machine leaving a loud mess in its wake."

  His tongue throbbed. Right, he was biting it again. Creating his own list of people he didn't like and adding wise guys to it felt very important all of a sudden. Would they go above or below scientists? He ended the call and rapped his knuckles on the console to get Re-5's attention.

  "Status update?"

  "We've found one of the three, sir. The WAV is prone."

  He ground his teeth. "And the other two signals?"

  "You'd have to ask the echo room or the analytics compartment." He did.

  The engineer who answered him sounded peeved. Annoyed he'd interrupted her work? "We're still calibrating the scope and range of the SWOD impulses, sir. They would've felt incentivized to avoid the crowded paths. Stick to the lesser tunnels. If we can--"

  The command compartment shook. Stronger tremors. He actually lost his footing. Re-5 almost tumbled over the guardrails of their platform. Below them were cries of alarm as similar situations took place. They hadn't rammed something this time. It was the other way around.

  He pulled Re-5 away from the edge and made her stand beside him. If that happened again, better they stay near the center and have something bolted to the floor to grab. "Check on the status of each compartment, will you?"

  She looked startled, her mouth still in a silent "O" from nearly falling. "I-yep!" she squeaked. He felt it was a necessary courtesy not to bring up her pitch.

  Changing screens, Ze-4 spared enough mind to address the engineer still on the other end. "I'm not interested in the explanations. Get me some results we can work with!"

  Re-5 muttered under her breath. He overheard a few disjointed chains of words. "...casualties...unexpected impact...off proper course...not expecting repeats...movement to the medical compartment...locating the rest of..."

  He tasked one of the autonomous intelligences at his beck and call to locate the disturbance. It scoured through the Titan's feeds in every direction, and he got an answer before Re-5 finished her work.

  A blue Aud was the culprit. It'd latched onto the side of one of the center-to-rear compartments. Their unwanted hitchhiker tore through the scutumsteel plates. Their accumulated weight would hold for a bit, but he needed it off now. A breach near the center of the Nyx Breaker's body would be disastrous, even if the blue didn't get in.

  Damn it. Ze-4 didn't want to be the sitesman to field test the Nyx Breaker's other signature system. Some of the entries on the test list looked dubious. He'd given them red flags, though he hadn't interfered with Re-5 if she chose to go ahead and test them. He gave her responsibility after all, and with her responsibility came autonomy.

  Why the red flags? Some weren't all that well tested before the design team added them to the Titan's design. He listened to his gut on others. There was a third category, too: some sounded too stupid, even once he tried to understand the logic behind their inclusions. The second half of this Titan's signature system fell into category two.

  But it wasn't meant to be. Either the Titan took the plunge, or the blue outside plunged inside sooner or later. It was a straightforward situation with a straightforward answer. Why was he consciously moderating his voice to hide the nerves when he reached for the mic, then?

  "Due to complications, we're recharting the paths. More accurately, we're making our own. All personnel, prepare to dive." Diving itself was a simple, harmless concept. For the most part. That was when taking into account who--or what--would be doing the diving.

  The Titan underwent some superficial changes while klaxons blared inside. The scutumsteel plating covering its body would angle out to deflect glancing blows by default.

  Now, they turned inward to meld against the Titan. The legs folded in on themselves, disappearing into slots underneath. The Nyx Breaker continued moving without them, relying on the anti-grav generators' output.

  Most notably, the nose of the Titan folded outward. Scutumsteel sliding away to reveal a repertoire of cluster drills beneath. They enlarged, extending out and already spinning. A shifting rack moved them down to the center of the head.

  Ze-4's eyes locked onto the projection with the blue Aud on it. "You're a clingy one. Let's see if you can keep your claws in after this."

  The Nyx Breaker shredded through one of the walls. It broke through a deeper barrier of earth, then another, then another. They left their disadvantaged position behind, propelled to fantastic speeds by their lack of traction.

  Re-5 directed some techs to control one of the systems differently in the background. He only heard her at all because he made a conscious effort to remain aware of other things. His eyes kept diverting back to the still-open projection of the blue.

  It stubbornly wedged its claws between two scutumsteel plates to anchor itself. Even as it got crushed between a never-ending tide of rocks and a Titan's broad side.

  This story has been unlawfully obtained without the author's consent. Report any appearances on Amazon.

  'Fall off already, will you? You're wasting time. Ours, yours, everybody's. I know you have something more important to be doing. Go away and sleep. Forever, preferably. That's called death, if you get curious.'

  He couldn't be the only person in the command compartment harboring ill will.

  Humanity feared all Aud, no matter their tier. Sometimes, that fear abated when humanity developed its next generation of weapons. It'd never disappeared. Not really. The weakest white-fur could break through sandwiched, normal steel like paper.

  The differences between each tier weren't like taking a step at all. That was what the Light Institute had taught naive, little, ten-year-old him. It was more like running a kilometer.

  Yellows weren't at the halfway point yet, but they alone'd made it clear humans and WAVs were no longer enough. If a serviceman got too close to a high-tiered Aud, most of them already assumed they were dead soldiers walking.

  The hitchhiker was still there. Although the apex of what the Aud could become wasn't higher than purple, that was for raw power. There were more mundane qualities to consider. Perception, recognition skills, and adaptive learning all differed from Aud to Aud.

  It disappointed him that out of all the possibilities, they'd gotten a stalwart and stubborn member of the enemy. The Titan tore through rock layers, adding its own lesser tunnel to the greater structure. Ze-4's eye twitched, watching the blue not only manage to hold on, but continue digging. What a day this was turning out to be.

  The Titan was moving agonizingly fast to stay at a constant speed while drilling. What it was accomplishing was far from easy work, no matter how much technology it had piled inside.

  Regardless, the blue Aud refused to succumb to either of the ideal outcomes. It never detached. If the first ten seconds of grinding it to death didn't work as it stayed trapped on the Titan's exterior, more time wouldn't change that. It was safe for the most part, now, inside its forming tunnel.

  He could believe it, but at the same time, he couldn't. He also expected it wouldn't die from that treatment. It endured a punishment that'd generated enough heat to melt whole tons of scutumsteel.

  Ze-4 checked the nearby tunnels. They were in a moderate-sized air pocket, losing depth while moving further west. Too far west? At the edge of the map, he could see where the known tunnels ended and knew he didn't want them to end up in that region.

  The blue did something outside to create another tremor in the command compartment. Already, he felt like he was at his wits' end. He didn't want to command anything for at least an hour. Hitting something sounded far nicer in his head.

  "Take over as acting sitesman. Try to keep us on course."

  He was on the ladder when she looked up from her communicator. Unlike most servicemen, she'd sacrificed some of her flesh for cybernetic enhancements. For "greater efficiency out in the field", her submitted application had said.

  Yep. As if all but forcing him to helm the Nyx Breaker wasn't enough, the head generals made him sort through the crew, too. Which one would he bide his time for, so he could kick them under a table?

  Her projected HUD split so she could stare at him. Squint at him, more like. "Where are you going, sir?"

  "I have something to check. An idea. I won't be a minute!"

  For carriers of the Old Man's Blessing, their old age really felt like a number. An actual number, a statistic on a screen. Nothing more than that. For Ancients, getting it, while rare, was a signature trait. Sometimes younger servicemen got lucky and joined their ranks.

  Every Blessed had enhanced physical and mental traits. Better eyesight. Smoother skin. Faster reactions. Natural strength and speed. They were desirable to have at the forefront of any Aud-human conflict.

  The effects of the Old Man's Blessing on his own mobility were easy to catch. It was less clear to see when he moved like anyone else. He'd used it to avoid getting in anyone's way or tripping a hurrying tech by accident.

  But now that the clock was against him? Ze-4 moved in a way that contradicted his Ancient status. His Vigor, the other half of the Blessing, made him the fastest human alive.

  He was a blur. Climbing the ladder took a second, and he weaved around anyone in his way to reach the next command platform. If someone blinked, it'd be easy to miss him. Re-5 watched him disappear from the lowest command platform and pushed him from her mind.

  She gripped the edges of the command console. Her HUD made queries to an autonomous intelligence. "If the anti-grav output isn't already full, get us to that point. We need a buffer to avoid nicking something better left alone and causing a collapse behind us."

  Outside the command compartment, Ze-4 moved with urgency. He stopped by a neighboring one to recruit the first three engineers he saw. "Meet me down by where the banging will originate. Take long enough, and you'll start to hear it."

  He zipped further down the Nyx Breaker, almost to its tail, before stopping. One of the stores was back here. Where were they? He tried to take his time going through the shelves and storage containers, so as not to miss anything.

  The things he needed gradually found their way into his hands. A tripod, three power cores, a barrel, and several other items. The assortment would've seemed completely random to an observer. He was spared the need to explain to any inventory management. They were huddled away in the safer areas of the Nyx Breaker. Non-military personnel.

  That was a pointless differentiation, though. They were all on a Titan. They wouldn't've become crew members if they weren't capable of acting like members of the military. That made them all military personnel, which then invalidated--

  'Not the time for that.'

  Good, and he'd better leave it at that. He dashed back, stopping at a specific point in an empty corridor. The Nyx Breaker wasn't bipedal or quadrupedal. It lacked an easy internal layout for its crew to use for navigation. The design needed it to be capable of twisting its body and contorting itself.

  How did the engineers make a traditional compartment layout work then? They'd made the Nyx Breaker's insides a long line of essential rooms. The echo room, the command compartment, the garage, and the generator stores.

  Between them were the mundane or relatively unimportant ones. General goods stores, military depots, recreational and living spaces, and so on. Some of them connected front to back with the ones ahead or behind.

  But a serviceman onboard could access them all from a corridor stretching alongside the right side. Good thing the blue'd latched on from the side he could access with the corridor. If it did that with the other side, he'd have had to evacuate one of the compartments. The unlucky room might've been one of the essential ones.

  He didn't get to unfold the tripod before the trio of engineers showed. They waited for instructions. This was their trust in the sitesman at play. It worked fine that way, even if the integrated hero worship left a sour taste in his mouth. He tried for a smile.

  "One of you, hook all the cores into a single loop. They should pass energy one way only. Leave an opening to hook it to something else."

  One leaned down and scooped up the cores while the others stood by. Despite the killing machine meters away trying to get in, they looked more awkward than scared. He pulled the second over to the wall. The two of them leaned on it and ended up with their ears pressed against the cool surface. "Listen."

  They didn't need to strain to hear it. A routine, if irregular, thudding came through the scutumsteel. It was so strong, their cheeks rattled. The engineer paled.

  "That's the sound of the damn Aud making a mess of our Titan's shell. Tell me the exact second it starts sounding hollow, you hear?" The preparations would have to finish before then, but it was better to have a lookout than not. The engineer combined nodding and wiping his brow. "Good man."

  Ze-4 appraised the last engineer. She was eyeing the items he left in a pile at their feet, no doubt trying to guess what he had in mind. The other two would be no different. What they were about to help him create was something the Ancients used to do often.

  His generation hadn't been as conservative with their methods in the war. Most other Ancients disliked admitting the modern-day solutions had lower casualty rates. Ineffective, deluded old-timers, indeed.

  But desperate times called for desperate measures. He'd reach into that bag of distorted tricks again if it'd keep the Titan safe. "Can you make custom programs for these three?"

  He pushed an auto-coil, a scutumsteel biolock, and a microchip into her hands. "The first should get instructions to apply all its tension to a single cartridge. The second, erase its locking mechanism and set up something for voice commands. And the thi--actually, leave that be."

  The engineers needed two minutes to assemble their parts of the puzzle. Those minutes were the longest of Ze-4's life. Of the life of the engineer stationed beside the wall as well.

  He was sure that even if he looked outwardly at ease, his eyes reflected some of the anxiety in theirs. He could hide behind a wall of projected confidence, yet someone just had to know where to look to know him.

  The engineer in charge of the power cores had the simplest task. He opened a wiring kit and ran it through the ports jutting out on the side of the cylindrical cores. There was a visible spark each time he made a successful connection.

  Ze-4 watched as he flinched away once when he'd gotten too close, discarding caution for a better view. He made a few adjustments and had to double back when he ran the length the wrong way. Getting to test the speedy product wasn't in the sitesman's plans, so they would have to hope he hadn't made mistakes.

  The engineer, or rather, tech, assigned to the wider variety of items was slower. It was understandable. She couldn't run some wires through and call it finished. She needed to crack open the insides, sync her HUD, and retrain the software. Outsourcing the work to supportive autonomous intelligences only helped so much.

  The auto-coil had wound even tighter than its default state. This would wear down the component if used repeatedly, but Ze-4 only needed it to last for one go. The biolock got a new locking mechanism that reacted to his voice.

  He made a face at the microchip discarded in the pile. As much as he wanted to change his mind and have the tech work in it too, they were already short on time.

  He glanced at the lookout. Nothing was out of place yet. But the Aud outside had dug through more protective layers. Its blows were rocking the bulkheads lining the walls and the panels covering the floor.

  "Done?" He crouched beside the two.

  "They're as ready as they'll be, sir."

  He took the modified components and gave them a once-over. Indeed, they would either perform as he hoped they would, or the Aud would get inside and they'd all die. Very nice contrast. Do well or die poorly.

  He sent the three away, their parts over. He turned his back while they left. They'd make for the nearest compartment and seal the door behind them. He would stay here, assembling a welcoming present for their friend outside. He hadn't seen it in ages.

  "Do-2, this is for you." For everyone at Clyvis. The first time he'd made the turret was for an experiment. It hadn't targeted the Aud. He was so sure he'd made a mistake with the software. Couldn't imagine the errors weren't with it. But he'd needed help. Wouldn't have survived without...

  "Not. Now. Pay attention, fool."

  The tripod was the base upon which a sonic emitter slotted into place. He'd loaded a single cartridge into it. Its barrel had extra length from the one he'd grabbed from storage. The auto-coil was already screwed inside. He rolled the biolock around the legs of the tripod and connected it under the barrel. That locked everything in place.

  He grimaced at the makeshift turret's barrel. Here came the lousy part. His hand chopped down, smashing it in. He'd moved it so fast it only registered to his eyes as a blur.

  His eyes. He took hold of the dented metal, squeezed it, then struck it again when it didn't relent. A few strikes later, it was turning red from the heat, and his hands steamed through his skinsuit.

  The sitesman ignored the stinging and squeezed. This time, the barrel molded under his grip, the end twisting smaller and smaller. The original opening hadn't been larger than his thumb, but he needed it compressed more. His hands forced him to stop going any further. He shone a light down it to see if there was still an opening.

  The tri-core went into the powering chamber. He left that open. With three of them inside, the cover wouldn't have closed. He attached a light mount to trace the spot he aimed at with the completed thing. That should be near where the blue bastard would come through.

  As the final touch, he fiddled with the emplacement's firing settings. It would fire the cartridge at a respectable speed under normal circumstances. These weren't normal circumstances, though.

  By the Directory, he wished they were. He'd pushed it past the recommended safety limit and increased the energy input. How everything played out from here would count on a single shot.

  His tongue was tingling. Too warm. His throat felt itchy. He scratched.

  That was it. With the preparations done, he sat on the floor beside the tripod and crossed his arms. It could take a minute. He uncrossed his arms, tensing his knees and ready to spring up. It could take ten seconds. The next heartbeat.

  He was four times through that routine before he huffed a breath and stood up. If he was too jittery to wait, he'd use the energy for something productive.

  He looked to his left and right, pleased the command compartment had disseminated his orders. All compartments inside the Nyx Breaker had sealed doors. No one, military or otherwise, was walking in the corridor. He used the false privacy to do some light stretching.

  For compartments further away than twenty meters, there wouldn't have been much risk. Ze-4 didn't like thinking "there wasn't much risk."

  That mentality never meshed well with combat against the Aud. Those under his command were important. He leaned back, arms reaching up while he heard pops in his chest. And annoying enough to help him decide whether he wanted to continue being the sitesman here.

  But important. While some Ancients also served on the Titan with him, most of the officers and servicemen he led were decades younger. The future felt ugly. Though when didn't it?

  The Aud made it hard to appreciate that they still had a future. Pests, that was all they were. Unrivaled, deadly pests.

  He jerked and looked up from under the crook of his elbow. The bulkhead the tripod faced jutted inward. His eyes crawled up and down the new bulge. It wasn't two seconds before another thud hit it, pushing it in further. It was ready to give.

  He untangled himself and scrambled to his feet. He'd love to fire prematurely. The scutumsteel was still protecting him and everyone else from their blue buddy. What better time to catch the blue unawares with a solid shot to what he'd hope was the head?

  At the same time, the same plates of scutumsteel keeping the Aud out also protected it against his trump card. Scutumsteel was a hardy alloy so dense and tough, it could withstand Aud charges head-on. So long as enough of it got sandwiched together.

  How long the plates had held under the Aud's relentless assault was a testament to this. But that meant projectiles would lose some momentum before punching through. He wanted to strike at an Aud staring him down, not an Aud still behind solid blocks of thick metal. The cartridge couldn't lose a single iota of bite along the way.