So, I said I was out of hints, but then my Chemistry teacher accidently gave me an idea for another one, so let's see if you've been paying attention in school. He explained that when you dissolve an acid in water, H+ ions will split of the acid and attach themselves to the water molecules. This splitting process has a special name (starting with "dis…", I won't tell you more) which sounds similar to the thing that Annabeth has. I hope at least one of you pays enough attention in school to find this helpful and answer my question.

Again, the EULA demands I post a story so here you go.

Nico

I was on an important mission. One that would help save the lives of many future campers. I was tasked with getting some medical supplies from a pharmacy in Manhattan. I had no idea why I had even volunteered to do this, Will had announced that it needed to be done and I had said that I'd do it. Sometimes I did weird things. It must have had something to do with the jar situation, getting no oxygen for five days had really messed with me. Whatever the case, I left the store with everything we needed when I heard something next to me. I turned to see an Empousa standing next to me. "Hey there handsome young man" she said, clearly with charm speak. I realized that what I had seen as a flaw for so long would now become an advantage. "Don't even try that. Your charm speak will not affect me for I possess a protection you cannot comprehend." "What protection would that be?" "It's quite simple actually" I opened my jacket, revealing a rainbow pattern on the inside. "I'm gay"

Something told me the Empousa had not been expecting that. Luckily (at least for her, for me it kind of sucked) she had more tricks up her sleeve. She charged at me and I fell to the ground. I was about to shadow travel away (against Will's orders) when I realized that I had dropped the bag. I could not give Will two reasons to kill me. I first had to get the bag back, and then I could execute my getaway. I didn't have my sword with me (It's not like I can just put it in my pocket like riptide) so I had to come up with something else. I summoned a skeleton (Europe is so much better for that, The empires that existed over the millennia have pretty much littered the ground with corpses, but finding a skeleton in new York was a lot harder. After finding no human skeletons within range, I went for a dog buried in central park. Without weapons, dogs are better fighters anyways, at least the big ones. On its own, the skeleton was still too weak though, so I had to help it by making its bones stronger or something. I don't know what exactly I did, I'm not Annabeth, just that it helped the dog. And, how else could it be, it drained my energy. Over the two and a half years since Percy, Annabeth, Thalia and Grover had found me at my school, I had been getting better and better at using my powers, and it had become less draining to use them, but Tartarus had set me back quite a bit and over exerting myself to bring the Athena Parthenos to camp probably didn't help the situation. Why didn't the 7 decide to get that thing to the US before bringing it all the way from Rome to Epirus? Anyways, the Empousa finally fled after finding she could not beat me. But at that point, I myself was so exhausted that I felt like I'd fall asleep soon. I grabbed my bag and finally shadow traveled away. As I was dissolving into shadow, I knew I didn't have enough energy left for the trip to the tip of long island, so, with my brain already halfway off, I aimed for the nearest safe place. When I left the shadows, I was in a room I vaguely recognized before passing out.

When I woke up, I was laying on a couch. I blinked a few times and looked around. Now I recognized where I was. A place I hadn't expected my brain to go to when looking for the nearest safe place. The Jackson apartment. As if she had felt my awakening, Sally came in just seconds later. Someone else also came in. I didn't see anyone, but I could sense another soul appearing. "Miss Jackson, what are you doing here?" I asked. Then I remember that this was her house and corrected myself. "Sorry, what am I doing here?" "You, uh, showed up on my living room floor, passed out. You're Nico, right? The one who gave my son invulnerability?" "Yes, Curse of Achilles. I think he still doesn't understand that I was trying to show him that I liked him" "You liked him? Like, in a romantic way?" Had I actually just said that? "I thought I did, but Percy just isn't my type. So to go back to your original question: Yes, I am Nico, the one who made Percy invulnerable." I looked around, trying to find the second person. "Okay, but that that still doesn't explain why you were passed out in my living room." "Well, I wanted to shadow travel to camp, but I had fought monsters before, so I didn't have enough energy for the whole trip, so I kind of ended up here. How long even was I here for?" "So, it's still the tenth, don't worry." That was good, I had had some bad experiences with missing multiple days. Did I say days? I meant decades. "I found you around twelve, so seven hours ago."

She moved closer to me and I could now make out that the second soul wasn't moving around freely but was instead spatially bound to Sally. Was she possessed? No, eidola and similar ghosts felt different. This thing just felt… young. Then I finally understood. "Congrats" I said. "Congrats on what?" "Well, you're either possessed by a super young ghost, or you're pregnant. But there's definitely a second soul present within you. I assumed it's the latter." "Well, you assumed correctly. I'm at the third month. Now, is there anything else I can do for you?" "Don't worry, I'm fine" I tried to sit up and noticed that I was not really fine. I had some injuries from my fight and others from crash landing on the living room floor. "Just get me my bag, and then I'll leave." Sally left and returned about a minute later with my stuff. "Thanks, I'll be on my way now" "Nico, I can see you're hurt. At least take this" She tossed me a piece of ambrosia. Where did a mortal woman even get that? "Don't worry Nico; I got enough of this stuff. My apartment is basically an outpost of camp half blood, so I always have some demigod supplies here." I ate the piece of ambrosia and felt it heal my wounds and reenergize me. "Thanks again, see you soon" I said before dissolving into shadows again.

This time, I made it to camp. I managed to land right on one of the free Infirmary beds. Will saw me and came running towards me. "Nico, where in Hades have you been?" "Well, not in Hades but I know what you mean. I just tried shadow traveling back and passed out for around seven hours. No big deal" "No big deal? Nico, do you have any idea what can happen to a demigod in 7 hours?" "In my case nothing. I didn't pass out right where I started; I already got a few kilometers behind me before dropping out of the shadows at Percy's place. Sally waited for me to wake up and then gave me some ambrosia before I went back." "Okay, but why did you pass out from shadow traveling once? If your powers are decreasing further or becoming more draining, we need to monitor that." "Oh, I was already tired beforehand, from summoning skeletons to defend myself against an Empousa." "Oh, I hate those things. First they charm speak you and then they kill you." "I actually got lucky there and was able to resist her using the power of gay. Anyways, my powers drained me like normal and I've got the supplies." I handed will the bag. "Good, now, no shadow traveling for at least 36 hours. Doctors order. Instead, you can help me on my project on immortal DNA. A really interesting related aspect is clear sight and how it is passed down. Do you happen to know any children of clear sighted mortals?" "Well, I do know one, but they unfortunately won't be born for another six months or so. Sally's kid. Their soul felt familiar for some reason."

So, this was my second Bonus Chapter. The Original idea for Nico sensing someone's child actually comes from a headcanon I read a few months ago, except there someone else was pregnant. Hope you enjoyed it.