I use magic sense to search for elves in the city, and I sense a cluster of them towards the eastern outskirts. Without another word, I fly us towards them.
As we make our there, I sense Nina's agitation, and she doesn't waste time explaining it.
[So, you and the elf girl are friends now, hmm, Mizuki? That's very interesting, you see, because you used to insist that we were just 'friends'. Do you remember all the things you used to do with me, your 'friend', Mizuki? I was just curious, what kind of friends are you and the elf then?] (Nina)
I'm trying to suppress my amusement, so she doesn't sense it through our connection.
[No need to worry, I was mostly joking. I promise you that our relationship will always come first. By the way, I was very impressed with how polite you were, and I appreciate your restraint! As a thank you, I promise to grant you any request within my power after all this is over. So, are we good?] (Mizuki)
I sense a flood of emotions from Nina during my message, but it ends with excitement from her. After a moment, she responds.
[Yes, we're good, Mizuki, and I already know what I want to ask for!] (Nina)
Her tone could be described as mischievous, and it is unsettling, but I don't have time to worry about that now. We're approaching the slaves.
We seem to be at the very outskirts of the city, in a less developed area. There are lots of large barn-like structures, presumably storage warehouses. I use a combination of magic sense and my vision to discern the warehouse that I think is our target. From what I sense, the elven slaves are indeed underground.
I broaden my magic sense to all magic signatures, and I scan the area around our target warehouse. From what I can tell, all nearby people are just outside the warehouse, inside it, or under it.
[Nina, it's easier for me to remain concealed if I just set you down on the roof of the target building while I clear the place out. You'll need to refrain from moving on the roof, since you won't have concealment. Please use your bow to very silently take out any guards that I miss, or any others that start coming this way. Is that all okay with you?] (Mizuki)
I feel Nina squeeze me, and sense that she's still abuzz with excitement.
[Sure, no problem!] (Nina)
Alright, that was scarily easy, but I'll take it. I lower Nina to the roof of the target warehouse and drop her off near the edge overlooking the front entrance, so that she'll have a good vantage point. Then, I set myself down on a side of the warehouse with no guards. Showtime.
I pull out my katana, then activate max body and weapon enhancement, concealment with wider ranged silencing, and max time slow. I use magic sense to plot out my route around the building…there are four outside guards patrolling.
I take off as fast as I can towards the nearest one and he comes into view around the corner of the warehouse. As I get behind him, I see his expression start to change slightly in slow motion. Before he can fully realize anything, though, I stab him through the back of the neck and drop his body.
I continue around the building like this as quickly as I can until all four guards are dead, then I drop the silencing and time spells and listen. No yells or alarms. I check magic sense for people, and there are no more outside the warehouse. The ones inside seem mostly stationary.
The first part is clear.
[Nina, keep watch please, I'm heading inside!] (Mizuk)
[Got it!] (Nina)
I reactivate my silencing spell, and I make my way to the warehouse door. I can't see through it, so I've got to open it. I check with magic sense, and nobody seems to be near the actual door. I expand my silencing spell to include the warehouse door, then I slowly open it just enough to slip in and shut it behind me.
Inside, there are several boxes and bins near the doors, and towards the back I can see six armed guards. Magic sense confirms that they're the only other people on this floor. Most are sitting on the floor chatting, and two are walking around in a kind of patrol. They should die first.
Nobody seems to have noticed the door, probably thanks to the boxes around here and the silencing spell. I reactivate my max time spell, then lunge towards the nearest guard.
I stab him through the front of his neck, then immediately move to the second patrol and stab him in the neck from behind. As I glance back at the first patrol, I see in slowed time that his body is most of the way towards hitting the ground. I've got to hurry. I lunge towards the three seated guards and begin taking them out the same way.
By the time I'm about to stab the second seated guard, the third one is already starting to stand up in slow motion. As I stab the second guard, I expand my silencing spell so the last guard can't call for help. After I do, I lunge forward and stab him through the front of the neck. Then, I keep the silencing spell but drop the time spell. After his body settles on the floor, I drop the silencing spell and listen.