The sound echoing through the alcove we’d slept in was deafening on a level beyond what I’d experienced in any firefight so far. There were so many rapid cracks that it sounded more like hundreds of people shooting than the eight people we had down here.

  Given that included me and five others who should have been asleep, it was even more surprising. Those turrets Harold brought were more impressive than I’d anticipated.

  Just as I thought about the man, Harold’s impressive bellow rose above the din, shouting for us to reinforce the two on watch. While the man sounded as unflappable as ever, the fact that he even needed support with so much firepower behind him was concerning.

  Worry snapped me into full alertness, and I hurried to get upright. The motion was a little awkward while wearing my heavy armor, but I eventually managed to roll onto my knees and then push myself upright.

  For a normal person, sleeping in even my well-designed armor would have been agonizing, but my restored Toughness stat made it merely unpleasant. It wasn’t something I’d do by choice, but in dangerous situations it was invaluable.

  Beside me, Linnea was shrugging on a basic flak vest in lieu of her usual armor, and within moments we’d both grabbed our weapons and jogged out of our tent.

  The endless plasma fire still drowned out almost all sound as we got our bearings. Around us, the other mercenaries were joining us in rushing out, dressed in a bizarre mixture of armor and sleeping wear.

  I took in the sight with concern, even as I began sprinting towards the source of the noise. Only a couple of the others had anything close to what I’d call sufficient armor to withstand an attack.

  I’d have to move to the front and try to absorb the worst of the damage if the turret line was breached.

  By the time I’d come to that grim conclusion, we’d covered enough ground that the turrets came into sight. We’d placed them a few hundred feet ahead to give us time to assemble if an attack came, but it looked like we were still almost too late.

  Ahead of me, Harold stood beside Jamie between the four turrets, both of them adding their own firepower to the barrage of plasma. Beyond them was what at first looked like a moving, black wall.

  As we moved closer, my confusion turned to horror as I realized what we were looking at.

  The attack was headed by a line of heavily armored spiders. They advanced slowly, no doubt hindered as much by the sheer weight of their carapace as they were by our attacks.

  Their armor cracked with every shot, forming deep craters and scars, yet they continued to march forward.

  “We took a couple down with grenades!” Harold roared as we approached, somehow noticing us without turning around. “But they’ve been moving unopposed since then. We need heavy support to expose the main force.”

  Beside me, Linnea was already moving to unsling her plasma cannon. Two of the other mercenaries joined her in readying similar weapons, while the rest pulled grenades.

  I joined the second group, pulling a plasma grenade off my bandoleer. In a move we’d practiced for just this situation, I timed my throw with the others for maximum effect.

  The combined explosion we generated was enough to disintegrate the middle two armored spiders and sent the ones on either side reeling. It looked like a victory, until the smoke cleared to reveal another line behind the first.

  I cursed under my breath, the sound vanishing into the din. If this attack was nothing but armoured spiders, we were in for a hell of a time. I could only hope they lacked the resources to produce that many.

  We at least stalled the march long enough for the trio of heavy weapons to prepare, and they followed our grenade attack with an even greater explosion. It struck with enough force to fell the remainder of the front line, and had me looking at the roof in concern.

  A cave-in might save us from the spiders, but it would be a hell of a task to dig out. And that was assuming it didn't take us out as well.

  Thankfully, the crater we’d blown in the roof revealed only solid rock underneath and showed no sign of collapsing. If only we were as lucky with the spiders.

  When the dust cleared, we were once again facing a fresh line of armored spiders.

  It was a long and grueling fight before we managed to clear out the enemy.

  In the end, the front third of the attack was formed of the resilient spiders, and even with heavy weapon support, they’d advanced to the very edge of our turrets before we took them down.

  Unauthorized duplication: this narrative has been taken without consent. Report sightings.

  In the process, we also expended every grenade we had, leaving us to fight the remainder of the horde with our standard weaponry. Given how close they were, this included advancing to protect our turrets.

  They were incredibly expensive pieces of equipment that we had no replacements for, and were thus an invaluable part of our expedition. I wouldn’t want to trade them for someone's life, but I was willing to put people in danger for them.

  Myself included.

  If the remainder of the attack had been filled with more advanced variants, then we might well have had to use our temporary shield generator and abandon our gear. As it was, even the horde of regular giant spiders tested us.

  By the time the last spider fell, six of us were injured, two badly enough that they would need to return to base camp for treatment. If not for my Toughness, I would have been among them.

  With it I was able to withstand wounds that would fell a normal person, allowing me to stay with minimal medical attention. This was something Harold found less than pleasing, but in the end, I was able to convince him that I would be fine in a day or two.

  The aftermath of the attack stalled us for a full day as we replaced the two wounded from our reserves and shipped in a new load of grenades and ammo. It would have taken even longer if our slow progress hadn’t worked in our favor.

  Soon, we would be more than a day’s travel from the surface and would have to seriously consider moving our base camp up. It would expose them to potential danger, but if we didn’t, we risked maneuvers like this taking days.

  That night, I don’t think anyone slept well; however, our fears of an attack didn’t eventuate. It was further confirmation of my suspicions about our enemy being limited in their resources.

  After that last attack, I was reasonably confident there were two such limitations.

  The first was the available biomass, for want of a better term. This was probably a limit on the total number of spiders they could create. Originally, they’d cheated at this by somehow recycling their own dead, but that was no longer possible.

  In our latest series of victories, we had secured all the dead and sent them back to the surface via maintenance bots. Our enemy was still producing more, but it seemed to take several days to mount a new attack.

  The second seemed to be some kind of limit on the more complex spiders. I didn’t know if this was time-related or something else, but I did think it existed. Otherwise, the last attack would have been entirely advanced spiders, not a wall of armor protecting base variants.

  Combined, they gave us a solid chance for victory if we kept pushing. Even better, I suspected that the enemy was beginning to panic. If not, they could have waited a few more days to build up before launching an overwhelming assault.

  Perhaps this was the first time it had truly been threatened? Given the lack of adaptation we’d seen in the first few waves, that seemed like a reasonable assumption.

  Sharing my thoughts went a long way to boosting our group’s morale, and we pushed forward the next day with a renewed sense of hope.

  The main tunnel continued to reach ever wider alcoves as we advanced, until we finally reached a point where it opened out into a massive cavern. The space was so large that only the floor was lit, leaving the area above us a sea of darkness.

  I could only imagine we’d reached the main mine at last.

  “Looks like it’s another tunnel crossing us like an intersection,” I said as I interpreted the output of our scouting drone.

  It was similar to the models Elana used, though I couldn’t control it through a brain implant like she could. Nor was I able to pilot it very far by remote control, given the weak signal from our repeaters.

  Instead, I had been forced to spend a couple of hours setting up a basic program for it to scout ahead, and then more time for it to perform the actual scouting. It was well into our scheduled night by the time it returned, but I stubbornly waited for it.

  After finally seeing a change, I’d been hopeful that our enemy would be nearby. Instead, we’d simply encountered a far larger tunnel. One so large that we would have had trouble seeing the other side even if it were all lit.

  Worse, it extended in both directions to our left and right, leaving us with a conundrum. So far, we’d been able to secure the entire area behind us to protect our supply lines. I couldn’t see how we’d be able to do that and still explore one side of the tunnel.

  “Can I see?” Linnea asked from beside me in an adorably sleepy voice. She’d gotten a little sleep while I waited, but had insisted on being woken when the results came back. It seemed I wasn’t the only one eager to see the end of this.

  With a silent nod, I passed the portable hologram generator over. It formed a rendering of the long cavern above her hands, or at least the parts of it I’d been able to scout in a few hours.

  “We’ll have to follow one side until we reach a dead end,” Harold rumbled from behind us. The giant man was easily tall enough to look over both of our heads, and was already eyeing the hologram with concern.”

  “Yeah,” I sighed with concern. “But what about our supply lines? If we guess the side our their coming from, we might be fine. If not, the next attack will overrun the smaller tunnel. We can’t last more than a couple of days without extra water.”

  “I guess that answers the question of whether we need to move the base camp up,” Linnea said. “The edge of the tunnels is a pretty decent defensive position. Plenty of open space would let the reserves engage the enemy early, while still being able to pull back to the choke point if needed.”

  “Agreed,” Harold said, reaching an arm over our heads to gesture around the tunnel entrance. “We’ll leave the turrets behind to provide support. Without having to move each day, we can set up our mines and build some earthworks to create a real solid position.

  “That should offset the lesser numbers and let them survive a full attack.”

  I hummed, rubbing my chin as I thought it over. The lack of turrets would leave the forward team more vulnerable, but they’d still have the emergency generator. That would mean the reserve team wouldn’t have a guaranteed fall-back, but the extra defenses would hopefully offset that.

  “I can see that working,” I said after a little more consideration. “It will probably take two days to get everyone and our supplies down here. Do you think the two wounded will be combat capable by then, Harold?”

  “Good enough to stand still and shoot, at least,” the man chuckled. “And we can get a lot of the work done before they get here to make their lives easier.”

  “Nice,” I muttered as ideas flashed through my mind. “We’ll need to leave someone in command as well. Unless there’s someone in reserve you’d trust?”

  When Harold shook his head, I continued, “Right then. I hate to ask, Linnea, but would you mind…”

  “Actually, Lord Hope,” Harold cut in before I could finish. “I believe you would be the most suited to lead the rearguard.”