I watched from around a corner while Cluma demolished another group of goblin champions. Two went down at once, each clutching at their throats, then she stepped towards the other two, who were looking around in confusion. At that point, things did go slightly wrong, when she stepped on a pressure plate which must have escaped her [Trap Perception]. I saw the bolt flying at her from behind, but she twisted and dodged with grace, despite not even looking, and the dart embedded itself in one of the two remaining goblins instead. They both died moments later, suffering stab wounds to the heart.

"Drat," she muttered. "I'm supposed to be levelling [Trap Perception], but I got [Threat perception] from that."

"I'm surprised it triggered, given that the bolt wouldn't have penetrated."

"I don't want my new outfit to get scratched on its first day! Of course it was a threat, even if it wouldn't have hurt me."

I blinked in surprise. Was that how the skill worked? She wanted to keep her armour pristine, so it detected the bolt as a threat even though, by my standards, it wasn't? Had my armour survived its first day of delving unharmed? Perhaps so, given that I didn't go deeper than floor two, but that was just because of weak enemies, not because I was trying to protect it. I mean, armour is supposed to protect the occupant, not the other way around!

Of course, I kept my thoughts to myself as the two of us removed the cores. A skill level was a skill level, and she wasn't stupid. If she got to a floor where she actually needed the protection, she wouldn't act like that.

Removing the cores took a matter of seconds, with the two of us having dismantling skills at or above level ten. They vanished into my [Item Box], and we moved on to the next group. And the next, and the next. An hour later, and we'd caused a considerable reduction in the population of the floor, but Cluma finally got her first level of [Trap Perception], and with it, yet another class level.

And she still hadn't taken a single scratch to her armour, on one occasion doing some impressive acrobatics to ensure that remained the case, having accidentally set off three dart traps at once.

"You're obviously overpowered for this floor. In fact, I don't see how any enemy in this dungeon could deal with you. Maybe the final boss could just throw their numbers around until one of them crashed into you, and you might struggle with the dart traps on floors nine and ten, but aside from that, I've got nothing. It's likely your [Monster Perception] isn't good enough to pick out the assassins on floor eight, but that doesn't mean much if they can't find you either."

"So we're going deeper now?"

"Might as well. Let's move to floor six, and if you have no trouble there, we'll do seven for the rest of the day."

"Aww, I wanted to clear the whole thing."

"We have to leave something to do tomorrow. But first, you have a fight to deal with that you've wanted for a long time. One I stole from you last time."

The invisible Cluma managed to nevertheless radiate confusion. "But I've never been here before?"

"You'll see."

We entered the boss chamber, where the orc stared in my direction, awaiting the start of the fight.

"Hah, so that's what you meant," said Cluma. "But I thought this was a goblin dungeon?"

"It is, mostly, but there's also some wolves and orcs thrown in. Anyway, go take your revenge."

The orc died, dual attacks simultaneously piercing its heart and slicing its throat.

"Oh! [Critical Strike] levelled up!" exclaimed Cluma happily. "That's three skill levels today!"

That was anticlimactic. Floor six went exactly the same way, with wolves dying and their poor riders having no clue what was going on, so, after a few packs, we decided to move to floor seven. With no queue for the boss chamber, and the path clearly visible to my [Mana Sight], we walked straight in.

As usual, Cluma walked over the line and the pack of five goblins completely failed to react. By this point, I almost felt sorry for the dungeon monsters. How do you fight what you can't see? Especially when you have an expected lifespan measured in seconds, and have no time to plan? Given the presence of the pair of goblin sages, I shut off my active scanning as she crossed the line, in case it let them see her, only for both to die moments later, their hearts pierced from behind.

The three heroes spun around at the dying gurgles of their brethren, but failed to see Cluma. The one hero armed with a bow took aim at me, so I beheaded him with [Far Reach], utilising the cutting portion of my sword-staff for the first time. The pair of melee-equipped heroes also turned towards me, being the only visible enemy in the room, and started to move. I ignored them, and spun my active mana scanner back up just in time to see Cluma launch a thrust at the back of the neck of a hero.

He ducked.

Cluma's movements stuttered, being so used to each enemy dying to one blow that she hadn't made contingency plans to deal with a failed attack, and that gave the hero time to turn and swing his sword in a wide arc in front of him. Cluma leapt backwards, executing a successful dodge, but the hero kept swinging. It was obvious he couldn't see her, given that he was still attacking Cluma's previous location and hadn't followed her move, but had reacted to the attack somehow.

The reaction had looked like [Threat Perception], but I'd never seen them avoid my blind [Far Reach] attacks like I had seen delvers do. Had they gained new abilities? Was it something similar, in the same way that the goblin assassins had their own enhanced version of [Stealth]?

I'd once read through the descriptions and abilities of every monster in this dungeon... What did it say about the goblin heroes? Right, there was something about sensing killing intent. So they weren't reacting to the weapon, but to Cluma herself. Well, it would do her some good to have an actual fight for once.

She once again moved behind the goblin, which didn't react, and thrust for his heart. This time she put her full speed behind the attack, and though the goblin tried to twist out of the way, it wasn't enough to avoid the attack. It was enough to avoid it piercing his heart though, and furthermore his continued twisting wrenched the dagger from Cluma's grasp. Cluma chased it, simultaneously reaching for her lost dagger and thrusting with her second, but that was the wrong choice.

The final hero was behind her, swinging his sword in a wide arc. Despite still being unable to see her, he was simply making a wide sweep in the direction from which the attack on his group-mate had come. Cluma was completely oblivious, obviously too secure in her invisibility to have considered a potential attack from a third party.

Her [Threat Perception] would presumably pick up the attack, but given its low level and how heavily she had committed herself to her attack on the injured goblin, I wasn't certain it would be in time for her to dodge. I leapt in with [Far Step] and parried the swing myself, the clang of the goblin's sword hitting my adamantite polearm immediately attracting Cluma's attention. With a quick swing, I reaped his life, a follow-up thrust stabbing out the heart of the final hero.

"You screwed up there," I said, but from the way her ears had flattened against her head, it was obvious she already knew. "Can you drop [Stealth] for a moment, please?"

A downcast looking catgirl popped into existence in front of me, staring intently at the ground.

"You didn't tell me they could use [Threat Perception]," she said quietly.

"I didn't know. It wasn't [Threat Perception]; it was something with very limited range, so it's not something I've seen them do before. I've never been close enough to them without being detected for it to kick in. But that wasn't your mistake; there's nothing wrong with missing an attack. You aren't the only one allowed to dodge. What you did wrong was to ignore the second enemy while focusing on your target. When you've been sparring, how often did you fight groups?"

"Against newbies, sometimes."

"I doubt they would have fought together effectively. And you've been fighting groups today, but when everything has gone down in one blow, it hasn't really mattered... You could do with a spot of teamwork training too." I pondered for a bit before deciding I would take a page from Xander's training manual. "Let's carry on as planned on floor seven, then tomorrow we'll try some more specialised exercises."

Cluma nodded and vanished again, then proceeded down the stairs where we resumed our culling of the local wolf population. The remainder of the day went without incident, and for the first time I made full use of [Item Box] to carry large amounts from the dungeon, filling it up with whole dire wolf corpses.

It wasn't an unsurmountable advantage, given spatial storage items, but it had the benefit that I could store things of any size without worrying if they'd fit through the container opening. It also had a large capacity and completely negated the weight. Even Grover's storage items only cut it by ninety percent.

Or at least, they used to... Could mum sew orichalcum spatial enlargement runes into a cloth bag? That would be cool... The bag I'd been given to carry my mythril in had long since degraded and lost its enchantment, but one that lacked that problem could be used for long-term storage. Or they could just make rigid chests from mythril now, I guess, but they would be less convenient to move around when empty. You wouldn't want to drag one into a dungeon.

When the time came to leave, I dealt with the boss myself, much to Cluma's disappointment. I needed to train too though, and I'd barely had a chance to use lightning against real opponents since getting [Expert Mana Control]. Four separate bolts of lightning cut through the air, and I could charge the glove fast enough for continuous discharge. Neither the goblin captain nor the wolf-riding knights had any ranged weapons, and all fell before they could reach me.

"That was cool!" exclaimed Cluma, having never seen it used against live opponents before.

We looted the chest and left the dungeon, returning to the surface in time to see the evening sunset in a red sky.

"That was fun! Are we doing the same tomorrow?"

"Not quite. Tomorrow we'll be working floor five again. You need to work on your awareness."

Another delver party that was hanging around talking to each other, presumably before splitting up for the day, turned around to stare at the teenager talking to the disembodied, slightly ethereal-sounding voice.

"And can you please undo [Stealth] when we're in public? It was funny for a while, but I'm worried I'm going to get a reputation here... As if I need more."

"Aww," said Cluma, but she nevertheless obediently appeared in front of me.

"We'll meet in the bar at fourth bell?"

"Okay!" exclaimed Cluma, before running home. I went to sell our loot, then ran home too, rather than teleporting, having not had much of a workout despite spending all day in a dungeon. Aside from the single occasion, I hadn't needed to step in to defend Cluma once, and she'd successfully finished the delve without her armour taking a single scratch.

At home the next morning, I borrowed a scrap of cloth from mum before teleporting to the guild. Cluma was already there, chatting animatedly to the barkeep. They must have been well acquainted, given how long she worked here. Her ears twitched at my arrival, before she turned around and saw me. She waved to the barkeep and hurried over, giving her usual diving hug as a greeting. She seemed to be over whatever it was that made her want to keep her distance, but the fact that she needed to wear an odour suppression enchantment to hug me was mortifying.

"You're late!" she complained.

"No, you're early," I answered, checking [Clock]. "Anyway, this is for you," I added, holding out the strip of cloth.

"Huh? It's just a strip of cheap cloth? What's it for?"

"For blindfolding yourself. Put it on under your helmet."

Cluma stared at me like I'd gone crazy. "Are you joking? How am I supposed to fight when I can't see?"

"Nope, no joke. Also, for today, you're banned from using [Stealth]."

Cluma stared at me like I'd just murdered a whole litter of kittens.