[Alright, that’s it.] Hazel said. [That’s just about the last of the engine’s stored mana.]

The Wisp regained control and looked at the door at the head of the hall. It had thankfully held against the monster, but not by much. It was sagging inwards greatly, and small cracks near the top and bottom let in an ear-splitting whistle and a small deluge of rainwater. Outside, the monster leaned against the door as it had for the last 6 hours. Every time the Wisp began to repair the door the monster would begin its assault anew, leaving it in worse condition than before, so the Wisp and Hazel had eventually decided to just leave it be for now, though the Wisp secretly wondered just how long the beast would wait before it started attacking the door of its own volition.

Despite the danger and noise, the Wisp couldn’t help but flare in contentment as he admired their handiwork. They had spent the majority of the last couple hours just building simple spike traps from the engineering menu into the floor, so that now the entire space between the gates was covered in crude spikes and pits. As well, large boulders hung tenuously attached to the ceiling, ready to be dropped with a simple mana signal, though Hazel had insisted none be placed over the now still fountain. Unfortunately, the Wisp had discovered that while force mana could mould and reform stone with ease, an actual supply of metal was required for any template that needed it, and even then it had to be formed and shaped using physical means to metal’s resistance to magic, so Hazel’s giant ballista idea had gone nowhere.

But while everything was set up and ready to let the beast in, the Wisp felt the depressing tug of caution stop it from just opening the door. While the Wisp had grown to greatly despise its new foe over the last several hours, it knew that facing the monster with a full mana storage would help if it could somehow counter the traps.

Or if it could fly, but the Wisp didn’t want to think about that scenario too much.

No, if they waited the monster might even leave of its own accord, which would be the cheapest option by far, and the Wisp’s internal mana-pincher was stronger than its sanguinity. Instead, the Wisp turned away from the whistling, leaking, cracked door and started to float towards the mana engine, closing the interior gate with a pulse of magic.

[Awwwww… We aren’t gonna watch?] Hazel whined. [But that's the best part!]

[Negative.] The Wisp responded. [We will wait for it to leave.]

[Why’d we place all those traps if we aren’t going to see them go off?] Hazel asked. [You can’t just set something up and not use it!]

[Preparation is the mother of success.] The Wisp quipped.

[I can’t sate my bloodlust with just preparation though.]

The Wisp floated towards the back of the room, straight past the engine and into the small box they had initially arrived in. Inside it was the same as when it had left, just smooth surfaces made of rock, and a runed keystone lying in the corner. The Wisp approached the keystone and telekinetically picked it up.

[Oh yeah, I almost forgot about this.] Hazel remarked distractedly. [We should probably lock this up somewhere.]

Keystones were an important object for wisps, or at least the Wisp thought so. It was soul bound to the Wisp, and contained intricate spellwork that let it use a physical form. Without it, its magical flames would be dispersed with a strong wind, and the Wisp would simply exist as a bare soul and core. Rather unhealthy, that.

But the Wisp wasn’t there to admire the spellwork however. The Wisp instead went back to where the tunnel leading into the room had previously been before the Wisp had covered it. Now it cleared the stone away from the opening again, and peered inside, ignoring the warm howling.

The tunnel seemed to stretch to eternity.

But more importantly, the tunnel seemed to be curve up from below farther inside, not from above or straight ahead like it had originally seemed.

[Our keystone arrived from the depths of the planet.] Hazel noted. [Huh. I’d assumed we were launched from somewhere else on the surface. I guess that explains why rain isn’t coming through.]

The Wisp had assumed so too, another mistaken urge. The Wisp flashed blue, not a little irritated that its predictions were coming up wrong more often than naught. Every question answered with yet more questions.

Sent to build a refuge from someone underground? What had happened to force such an action? The fact that the Wisp had knowledge on above ground ecology and resources but only the barest of its deep earth counterparts also confused the Wisp. Surely if it was programmed by sapients that lived below they would’ve given their refuge builder some of that. Unless they didn’t want the Wisp to delve back down for some reason. Did something lurk in the deep darkness that could wipe out a civilization that had discovered spellcoding?

That wouldn’t explain the wind however.

[Unit Hazel.] The Wisp thought. [What is your hypothesis on the destination of this bore hole?]

Hazel’s consciousness rumbled for a few seconds before she spoke. [I don’t really know. I’m guessing it leads to some sort of volcanic vent or deep cavern. That would be the simplest answer.]

The Wisp floated for a second before it backed off from the hole and covered it up again. Maybe later when the engine was secure the Wisp would send a small golem down to see where it led, but that would take some preparation. And a golemantic hall.

A sudden rumble shook the room, showering loose dirt over the keystone.

[Looks like it's trying again!] Hazel mentally jumped in excitement. [Come on, let's go see if the gate’ll hold!]

The Wisp suppressed a flicker as it dashed back towards the entrance hall. It couldn’t be too irritated though- the Wisp felt the same way.

…

[You’ve almost got it!] Hazel cheered. [Just a little more!]

The beast slammed into the gate again, a horrible groaning echoing through the hall as the metal bent and cracked.

[Concerning.] The Wisp flickered. It just couldn’t help it sometimes. [Has my fracture’s mind fractured?]

[Oh don’t be like that!] Hazel chided. [Do you not feel the call to battle? The rush before the storm?]

[Incomparable.] The Wisp idly tinkered with the mana stream going to the door. [Emotive potency remains muted.]

[I have to wonder sometimes how we came from the same soul.] The hall shuddered after another ram. [I seem to have gotten all the good parts.]

[Negative.] The Wisp dimmed its flames as one of the stone hinges snapped off. [Prepare for assault.]

With one last ear-splitting roar the door gave way to the monster, both flying off their remaining hinges and landing some distance away, and the monster strode into the entrance hall.

The beast was easily 3 metres tall, with a width half as much. Six hairy legs protruded from the back of the creature, bending around to the ground like a misshapen spider. It was longer than it was tall, though half of that could be attributed to its bushy black tail. Its head was shaped like a wolf, and what the Wisp had thought were pincers were actually two huge horns connected to its lower jaw. Most startlingly however, the monster had only one pure silver eye in the center of its head.

They didn’t get much time to balk before the hellspawn jumped into action, and it set a course straight for the Wisp.

It was agile, easily stepping between the stone spikes embedded in the ground. Even when one of its legs fell into one of the pitfalls, it quickly recovered and started using the sides of the spikes to walk on instead.

[Oh wow I hate it.] Hazel said. [So much wasted mana on those spikes…]

The Wisp didn’t respond, its focus taken up by sending mana pulses towards the rocks on the ceiling, which began to hurtle towards the monster.

Unfortunately, it’s eye seemed to be more useful in the dark than anticipated. As the Wisp sent its mana pulses to sever the rocks, the eyes followed, apparently able to see the invisible mana. It then simply dashed away from the rocks that the pulses went too, skittering away far before the rocks even began to fall.

The Wisp flickered as the demon avoided another, and when the monster came under another the Wisp simply threw a pulse at every rock left hanging, causing what looked like the entire ceiling to crash down on the monster. Dust and dirt shot into the air after the attack concluded, obscuring the entire cavern from view. The Wisp flared white in contentment.

[I think you might’ve got him.] The Wisp sent a small pulse at Hazel as she tempted fate. [What? Nothing could’ve survived that!]

The Wisp didn’t dare approach, waiting until the wind from outside began to clear the air. Only then did the Wisp telekinetically lift the rock it thought had crushed him.

Nothing was underneath it.

The Wisp instantly dashed upwards and scanned the room again. Its senses scoured every rock, spike, and pit looking for any trace of the monster. Had it fled?

A flash of black tugged at the corner of its vision.

The Wisp immediately ignited some ambient mana- a flame blast- and unleashed it behind its back. The blast ignited the mana in front of it, a small continuing explosive blast whose shockwave buffeted the flames of the Wisp. A loud yelping and sudden skittering greeted his attack, and the monster jumped backwards, slightly singed. Instead of attacking again however, it simply stared at the Wisp and growled, its pincers quivering.

[Unit Hazel has been upgraded to the second most irritating construct.] The Wisp said.

Hazel huffed but didn’t respond, probably not wanting to distract the Wisp in case it attacked again. A sensible move for once.

The beast moved, and the Wisp was ready. As the monster leaped off one of the spikes, the Wisp dashed into the roof and unleashed another blast. It was much weaker than the first though: the Wisp wasn’t made of infinite mana after all and igniting a bunch was an inelegant use of it. Much to the Wisp’s surprise however, the monster was ready for that, and seemed to twist its body in midair to avoid the blast, somehow able to project force on itself in midair. The Wisp was barely able to magically propel itself to the side to avoid the attack, the creature’s horns cutting through the Wisp’s flames.

[How?] The Wisp thought.

It didn’t give the Wisp enough time to think about it however, as the monster kept up on the pressure, leaping off walls, spikes, and fallen stones in an attempt to pull the Wisp down. Even the Wisp had to admit the demon was much faster than it had any right to be, and eventually the Wisp could feel its reserves approaching nil with all the mana boosting.

[Hazel. Open the…] The Wisp dodged a snap. [...interior door and be ready to…] Another leap nipped the core. [...redirect the mana flows on command!]

The door started opening, and as soon as a coin sized hole appeared the Wisp poured the majority of its remaining mana into launching itself towards the gate.

The monster didn’t take that kindly, and began leaping with blinding speed after them. Even with the magical propulsion, the Wisp only barely outsped the creature. The Wisp only hoped that Hazel would be quick.

[Ex. gate to In gate.] The Wisp commanded calmly.

Thankfully the Wisps were of one mind (literally and metaphorically) and Hazel redirected the mana flow from the destroyed outer gate to the inner one, having it flow directly through the open air instead of through the wall.

Right in the path of the monster.

It screamed as the energy hit it from behind, the sharp metallic smell of force searing off the outer layer of its skin filling the hall as the mana started shredding the fur to scraps. Before it had landed, it looked like the mana had seared off the back quarter of its hind legs and had taken sandpaper to its back.

The creature immediately galloped to the door on its remaining legs, only limping a little despite the damage. Above the remains of the destroyed gate, it took only one last look back and roared, the entire hall shaking in its hate. And then, it turned and ran out, hopefully never to be seen again.

The hall descended into silence for but a blissful second.

[I really thought it would continue the attack] Hazel noted, a touch of regret tinting her thoughts.

[An intriguing specimen. It appeared to have mana sight.] The Wisp lifted itself a foot off the floor. [We are lucky it ran, our internal mana reserves are depleted.]

[Bah!] Hazel disconnected the invisible mana flow between the gates. [It probably would’ve had to break down this gate to get through. We would’ve had plenty of time to recover!]

The Wisp began the arduous task of fixing up the place, starting with the door, but it couldn’t stop thinking about the beast. Why had it been so fixated on attacking them? Most beasts would’ve given up after the gate was closed, but to break in and then fight through all the traps and attacks? It had almost felt like an assassin sent specifically to destroy the fortress, which the Wisp initially dismissed as ridiculous.

But with how little they knew of the Wisp’s enemies, the Wisp thought, could they really be sure it wasn’t?