We clear the underground tunnels, and for the most part, I don't have to do anything. They turn out to be pretty narrow like I thought, so there isn't much room for me to use my magic. About the only time is when we meet ethereal ghost type enemies, highly resistant to physical attacks. I just fling a few dozen low level, barely synergized spells at them and they die. They're pretty weak to magic, and we only see like five of them.

I actually have to be somewhat careful. In such tight spaces, even if I cast my spells separately, if I do it too fast, I risk them colliding and synergizing into a horrifyingly random, uncontrolled cascade like earlier. It happens on a small scale a few times, drawing displeased looks from Liina that make me shrink away in shame, so I keep having to pull back my casting speed and use shorter duration spells so their spell timings don't overlap.

Despite the issues, it does make me realize something that could be useful if I learn how to control it.

Apparently, synergizing already cast spells can refresh and increase their durations.

I leave that for later, and just try to keep my head down and focus on doing my job without drawing any more attention from Liina. Or further punishments. That really hurt earlier, and I don't want to go through it again if I don't have to...

Besides small snips of communication, the group is silent, ears trained for signs of monsters lurking in the dark. It's pretty tense, but not as bad as it could be, because the monsters we engage are really weak.

The only exception are, there are these goat things with spiky antlers that show up sometimes. Unlike the goblins and occasional ghost, they're rough for our frontline to take on in such close quarters, and the uncomfortably hunched over healer has to use a few healing spells from time to time when Liina or the wolf-altra swordsman at the front with her get swiped by their sharp, branching horns.

I also hear Liina call for a map once in a while, which makes me wonder if my celestial has any sort of mapping ability. I try to focus on the idea, but I'm either not doing it right, or I don't have that sort of ability...

On our way, there's just one time that a goblin sneaks up on us from behind, easily dispatched with a hatchet through the forehead, and one other when one slips out of a blind turn as we pass.

For an instant, I'm worried about a repeat of my first quest, and my spells are already manifesting at a panicked pace, before a thrown hatchet brains that goblin too, pummeling it directly into the wall behind.

Apart from the few bumps and hiccups on the way down, things are pretty smooth.

Then we hit a goblin that screeches something fierce before Liina shoves her sword through its throat.

“Damn it, back up, get to that last choke point.” She says and we all start to retreat.

I start to pick up the sound of footsteps and clashing, scraping metal. Is it a swarm of monsters? Like those ones we hit during my first quest? What do we do in such tight spaces?

“Yumi,” Liina calls, making me jump and squeak from the unexpected shock. “Wear them down as they approach.”

“O-ok...” I answer uncertainly. How do I do that? Just launch a barrage of spells down the narrow tunnel at them? But that would turn into an uncontrolled cascade, and Liina would yell at me again.

One larger spell? I don't know if the tunnel could take something like that, I might collapse it and crush us all...

Something smaller? More controlled? I gulp, and start to cast. I fling a series of fire spells down the hall, aimed for the sides, followed immediately by wind before the fire has a chance to fizzle.

They mix and synergize, creating a series of tiny burning cyclones. They're only made of like four elements each, so they won't do much to the goblins, but I'm already shooting another round of fire to beef up the whirlwinds before they die out.

The wind begins to stretch through the narrow tunnel, nearly meeting, and I throw together a few somewhat larger earth spells, firing straight down the middle.

It all mixes together in flight, combining to fire a hail of sharp, flaming rock shards down the tunnel. There are dozens of pained squeals and screeches in response. Did that... actually work? It was only a small amount of magic, I mostly relied on the refreshing timers to keep them all up long enough to combine in the end, but the total number of elements I used hardly even came to thirty.

That's not enough to seriously damage a large group of goblins, is it?

As it turns out, yes and no. When they break into the torchlight, I see that my magic didn't kill the goblins, but it did injure them pretty badly.

Did I... do well enough? I don't know. Liina said to wear them down. Did she mean their numbers or just to hurt them? Either way, the fighting breaks out in earnest, Liina and the other swordsman clashing with the wave of goblins. Now that they're in front of me, I can't easily cast any magic past them.

I hesitate, unsure what to do. Is there any way to get my spells safely past without worrying about hitting my party members? The best I can do at first is flinging a couple earth spells up high and let them come down on their own further back in the crowd. But that gives me an idea. If I can control the magic after casting...

I throw a couple weak fireballs up high, then try and use my mana control on them in flight, curving their paths downward. It... sort of works. It's hard to redirect more than a few at a time, and I can't control their paths very quickly. By mixing with earth, I get something a little more aided by gravity, and just keep lobbing them overhead.

I try a few other mixes as I go, based on my earlier tests to have more spells release afterward, but I'm not getting much out of it. It doesn't matter, I'm still doing my job bombarding the group to wear them down.

“Disrupt!” Liina calls from time to time when they start to get overwhelmed or take a few too many stray hits for the healer to keep up with. When she says that, I charge a stronger wind spell and rush forward, blasting it down the corridor to knock away the nearby goblins and open up some space for us to regroup.

It was one of the only useful things I could do during my first quest, and now it's still quite effective, even if I have to use enough power in the spell to take a decent chunk out of my mana when I do it.

Whenever I have to break up the fight briefly, I try to use the opening to throw a quick burst of cascading magic down the hall while I have a clear line of sight, before ducking back into the cover of the others.

Good, as long as things are under control, this is no problem.

The goblins press us back a few times, but we mow them down well enough as the battle goes on, eventually finishing them up. Everyone takes a moment to relax before going to collect the leftover bits of bone, small weapons, and other various monster parts left after the bodies have dispersed.

I'm really glad monsters don't leave corpses. I don't think I could stand the sight of that much blood and gore...

We continue on, clearing the monsters. There are a few more large groups of goblins we have to grind down in longer bouts, and one time, it's even interrupted by a couple of those spiky goat things crashing through the entire battle. They end up killing a ton of the goblins in the process and even land a couple bad blows on the wolf swordsman at the front that take the healer a while to fix.

But we make it through.

“Damn this place is deep,” the wolf man says at one point.

“There's definitely something causing this infestation. The corruption's getting thick here, so I think it's not much further down,” the healer informs everyone. Not long after, the ceiling opens up some and she can finally straighten up with a long groan, and a few loud pops as she stretches her back after who knows how many hours hunched over.

The tunnel widens out and everyone tenses up. Why do I feel like we're about to get into a boss fight? Does this world have things like that? They did say it was something strong enough to cause a monster infestation... Maybe it's just like, some sort of magical artifact? Like a dungeon core or something, not a monster we have to kill?

My panicked hopes turn to fear as we peek around a corner into a larger room and see it. “Hobgoblin chief,” Liina says as we take cover again to avoid its notice. “Shouldn't be too bad, I've fought a few like this before. They like to summon hordes of smaller monsters.” She looks straight at me. “We've got some more space here, so we'll need some of your big spells to deal with any hordes. Don't hold back too much, but be careful you don't blow through your mana.”

With that terrifying responsibility suddenly lumped on me, I nod stiffly. Then Liina lays out the rest of the plan, mostly relying on her and the creepy hatchet fighter to focus on wearing down the boss while the healer keeps them patched up, and the wolf swordsman should be our mobile fighter, moving around to deal with any issues as they arise.

I try to tell myself it sounds just like a boss raid, but the idea that we're actually risking our lives here makes me queasy.

After checking our gear, we engage, rushing into the room with the large monster. As I run in behind, the room opens up and something changes somehow. I don't understand it, but I don't have time question it as the battle begins.

Gazing up, the monster mostly looks like the goblins, but larger, with more muscle and a big, horrifyingly rusted cleaver in one hand. It's a lighter green, hue shifted toward a sickly yellow, and like nine feet tall, outmatching even our healer by a solid few inches. While I hang back at the room's entrance with the fluffy healer and wolf, the other two rush in close.

Despite having rhino-like features and being even shorter than I am, the hatchet-wielder manages to keep pace with the taller Liina, flinging a few weapons up at the towering hobgoblin. It deflects a couple with its cleaver, but one finds purchase in its chest, and it roars angrily.

Waving the cleaver up overhead, the monster smashes it down, and the next thing I know, I'm being thrown down on my back, hard. From halfway across the damn room? While I'm struggling back to my feet, the boss roars, and monsters start digging out of the ground.

Dozens of squirmy little goblins slowly begin to drag themselves up around the boss.

“Fire!” Liina calls out, both of the frontliners jumping back to get clear. Liina, having seen my magic before, keeps retreating, but the rhino-altra doesn't.

“Back up!” I shout, already starting to form the spell. I hold it for a second, but it's about to fizzle, and the man still isn't moving, so I aim off to the side, away from him, and let the magic go. In a last ditch effort, I throw a cheap wind spell right after and desperately try to use my mana control to curve the magic correctly.

The first spell lands, a swarm of flaming meteors to crush and burn everything in a wide area... a little away from the hobgoblin, the horde of goblins, and hatchet man. It catches part of the group, away from him, but doesn't deal nearly as much damage as it should have for the amount of mana I dumped into it.

Damn it, didn't he see my lower power magic earlier!?

Just before the fire magic runs out, I get the gust of wind in place to synergize them into a flaming tornado, trying to drag the whole effect just a little closer. It helps, but not enough. I only get about half of the horde and clip the hobgoblin. Any closer and I might hit my idiot ally.

“What are you doing?!” Liina demands of the rhino-altra. He jerks, turning back to look at me with surprise written on his face, before retreating from the horde that starts to bear down on him.

“I thought she was a speed caster, the hell was that!?” he responds in kind.

By now, they've both retreated back toward our group, the goblin horde following.

“I'm a Synergist,” I explain shortly, already trying to figure out what sort of spell to deal with them, without burning too much more mana on it. “My strong spells have huge areas of effect, I've been practicing faster casting so I don't hit everyone! Liina told me to use my big spells!”

Liina suddenly flinches when I mention her for some reason, but keeps her attention on the incoming horde. Then I step forward. I think this should work...

I launch a few medium power fire and wind spells so they overlap and combine in flight, refreshing the duration of the ensuing flaming wind gusts long enough to crash over the long trail of goblins stretching across the room. They don't take that much mana, but they also leave the goblins scorched and heavily wounded, rather than dead.

“Good enough, recover your mana for the next horde,” Liina instructs before dashing away. I grimace. She's right, I used way more mana there than I should have. Because of that stupid perv...

I try to stand still and rest, to allow my mana to regenerate slightly faster, but I think I'm too tense for it to work very well.

The two frontliners rush in, hacking through the crowd of wounded goblins with ease to reach the larger enemy in the middle of the room. Despite its size, it's pretty fast, flinging that huge cleaver all over as they fight. But the two adventurers know what they're doing and keep baiting it into attacking one while the other hacks at it from the sides and back.

They work just like that to wear it down, until it roars for another group of goblins. It's even larger than the first, but both members retreat properly this time, so when I throw a near-full power spell, synergized specifically for maximum explosive power, it erupts over most of the room, wiping out nearly the entire horde in one go.

Somehow, despite being at the center of the explosion, the hobgoblin doesn't look much worse for wear. Is it really tough, or are normal goblins just that weak?

The wolf man whistles appreciatively at the results, and even Liina looks a bit shocked, since it's even larger than the scale of magic I used during our last quest. Magic like that is enough to put me on my ass for almost a half hour though, so I sink to my knees weakly.

I definitely don't have enough time to recover normally, so I start absorbing mana to regenerate faster, but I'm immediately assaulted by a wave of burning nausea. Why does the mana here feel so awful? Because of the monsters? Their bodies dispersing into mana in the air? The area itself? Or just the boss?

I have no idea, but I want to throw up.

Still, I know I don't have enough mana, so I keep going even as my stomach turns and my body starts to itch like I'm being dipped in acid. I'm so wobbly, I can't even rise to my feet, one hand to the ground, the other to my aching head.

It's a good thing too, because when the hobgoblin roars for a third group, it's even bigger than the first two, filling the large room corner to corner. Some of the goblins break from the ground directly beneath our feet.

“I've got it!” the wolf-altra calls, slicing up any in the immediate vicinity before they've even extracted themselves from the ground fully.

I hardly notice, I'm focused on my magic. A spell to cover a room like a hundred feet across? No matter how overly explosive they are, that's just ridiculous! Could I do the same thing as earlier on a larger scale? I don't know. Do I have enough mana? Do I have enough concentration?

My head's already killing me from absorbing mana like this, but I'm supposed to deal with the hordes, so that's what I'll do!

Drawing a deep breath, I straighten up as best I can on my knees like this. Then I start casting.

Almost a dozen simultaneous wind spells, spread out along the walls of the room. Not too high power so they don't burn too much mana.

Wind tends to have a longer duration than other magic, so it gives me the moment I need to summon matching fire-earth spells, with the focus on fire to get blades of magma. They chase the wind spells toward their destinations.

As soon as those spells are in flight, I grab out with my mana control, pulling on every part at once to collapse inward, toward the center of the room. It's slow, my control not letting me move them very fast at all, and their duration are quickly expiring.

That's why I'm already summoning waves of fire spells and launching them to refresh and beef up the tornadoes while I work on the next spell. Two large rocks that are set hopefully right to give wind explosions on impact. I'm not sure, I threw them together so fast I might have messed up the weaving of those.

With the fire, the big rocks go firing off around the edges of the room. They collide and synergize with all of the tornadoes along the way, growing more and more powerful, until they hit the far walls of the space. The bursts of wind from dozens of stacked elements blow all the goblins away from the sides of the room, and more importantly, launch the rocks toward the middle.

My aim was off, but I correct it with mana control while filling the air with dozens of lower power spells, aimed toward the middle of the room this time. It takes the last of my mana, nearly run dry after the slew of mid- and high- power spells that came before.

Then it all collides in the middle of the room. The synergized wind rocks crashing together near the hobgoblin to break into a massive whirlwind, flooded a moment later with dozens of alternating fire and water spells to keep the tornado swirling, the fire burning away the smaller goblins while the water releases as searing steam to blow out wide, whipping into anything out of range of the large tornado.

I keep casting, relying on the trickle of mana I'm getting from the environment to power my magic as the mana deprivation kicks in again and again, leaving me on my hands and knees. I can't even see where I'm aiming again, the awful surrounding mana being instantly converted into more magic as fast as I can pull it in.

I don't know how long I keep things going before it's too hard to continue. It might have only been five or ten seconds, it's hard to say. I can't even look up to see the state of the hobgoblin. I just hear sounds of combat after. They don't last long, I think, before Liina and the man return.

It's hard to understand what they're saying. I think I'm going to be sick. I actually do throw up a short time later, against one of the cave walls. Then I sit deliriously for a while, waiting for the after-effects of absorbing all of that horrible mana to start abating.

I'm too exhausted to move. At some point, Liina comes to crouch down in front of me. She holds up some bread and water, which I accept in a stupor. She even pats me on the head for some reason. “Good fight, good fight,” she says. Then a strange, unpleasant feeling washes over me. Did she just Scan me?

“Yup, thought so,” she says. “I guess we're both pretty lucky, aren't we?” Lucky how? I don't understand what she's talking about, and take a sip of the water, hoping it will help clear my head. It does a little, but not nearly enough to understand what she's talking about. Not in my current state. “Hey, don't take it too hard, I'm just not one to pass up such a perfect opportunity. It'll be fine.”

Why is everyone always telling me things will be fine?

“Activate Slave Crest.” Then there's a burning in my chest. I cringe a little, but I'm way too tired to fight it. It isn't until I feel the world closing in around me that I realize just how wide open it felt, just a moment before.

I slip halfway unconscious to the feeling of something closing around my neck and sound of Liina reciting a series of slave punishment commands.