(A/N: I don't own Percy Jackson! Rick Riordan does. Yes, the chapter title refers to a prophecy Ella recites in the Son of Neptune.)

Right when I climbed off Blackjack, an invisible force held me hostage from behind.

"Hey!" I shouted after I struggled my way out of its grip.

The invisible force started laughing and became visible.

"Did you get out early, too, Seaweed Brain?" asked Annabeth after she removed her Yankees cap.

"Um, sure. You could say that."

She keenly analyzed everyone else that came with me. When she observed Pearlcilina, she immediately tensed up. That might be because of the last time I escaped Goode with a girl, which didn't sit well with Annabeth. It's not like I'd date Pearlcilina instead anyways, though. I'd be more likely to date Medusa or Artemis. And no-don't get any ideas! I looked in Annabeth's bright gray eyes and shook my head no. She slyly smiled when she acknowledged my gesture. When she spotted Grover, she tensed again and knitted her eyebrows.

"Did an emergency happen? I was afraid that was why Grover rushed off with Blackjack. Is everyone okay?" she anxiously asked.

"I think so. Or at least hope so," Grover murmured.

Annabeth widened her stormy eyes. "What are you talking about?"

"There was a... f-fire- I think."

"Ahem?" Pearlcilina demanded.

"Grover, can you take her to Chiron?" Annabeth requested, more than slightly annoyed.

Grover swallowed. "Alright," he submitted.

I mouthed I'm so sorry, man to him as they strode towards the Big House.

"That's terrible!" Annabeth continued. "Wait...Percy, don't tell me it was you who-"

"I didn't do anything! Why is it always my fault?"

"Because your head is full of kelp, Seaweed Brain."

I glanced at Grover and Pearlcilina. Pearlcilina look frightened, even vulnerable. I would've felt bad for her if she wasn't so obnoxious. She sort of reminded me of myself when I first came here. That was it! She seemed so familiar, because she was like me. There was only one logical explanation...she was my twin! Okay, it actually was more wishful thinking than anything. I wished I had a twin ever since I was a child. We could switch places, do pranks, confuse people, and so much more! Plus, I was a lonely child. But with a girl twin, we can't quite do that. Still, a twin! That's pretty sweet. At the same time, I was a little angry with Poseidon for hiding her from me. But it was to protect her, right?

"Annabeth, does the fire alarm go off if the sprinklers do?" I asked.

"Yes, it's actually code. It's required that any sprinkling system would also have the fire alarm sound if it is activated," she informed. "So you did do it, then."

"No! Pearlcilina-," I protested.

Annabeth's expression hardened.

"It's not like that. I think she's my...twin," I sheepishly confessed.

She looked absolutely shocked, but it was obvious that she was trying to suppress a laugh as well.

"Percy, that's impossible! The oath...it doesn't exist anymore, but she wouldn't even be born yet..."

"I exist."

"You clearly exist; that's the difference. A child of the Big Three is far too powerful to go this far without being undetected by monsters and not be sent to Camp Half-Blood, or not be dead. You just can't expect a son of Zeus to randomly arrive here on a chariot or something. Nobody does. It just doesn't happen."

I scratched my head. "She could've been raised on Mount Olympus, the Underworld, or something."

She pinched the space between her eyes and shook her head. "Are you kidding me? All of us had substandard lives because we're supposed to be raised by our mortal parent in the mortal world. No one's that special, especially a child of Poseidon! No offense. What I mean is that no one, especially a forbidden child of the Big Three, would have stepped a foot into Mount Olympus for decades before the first summer you came. And the Underworld? Don't get me started, considering Hades' hatred of the Olympians and their children."

"But there's always a way! Everything is possible if you just believe in yourself!"

She now looked concerned again. "What are you even talking about?"

"Relax! I was just kidding- I wanted to see how you would react."

"Sure, Percy. Whatever you want to tell yourself."

"Hey! Besides, she could have been in a really stinky place, like me."

"Like what, a dump? Seaweed Brain, you do not have a sister, let alone twin," she grinned, while poking my chest at each staccato syllable.

"But she's so much like me," I smiled back. "She has flowing, jet-black hair and sparkling, sea-green eyes..."

Her smile immediately faded and she grimly said, "Seaweed Brain? Now it sounds like I have to worry about you falling for your so-called sister over me! Really, Percy? You don't even use those kind of words to describe me, your girlfriend! It's just...so unlike you."

"Well, I just wanted to sound more intelligent to feel less stupid around you. You know how teachers want you to be more descriptive? That's what I was doing."

Thankfully, her grim demeanor washed away and she started to laugh. Unfortunately, it was towards me.

"Unless you want to sound like a cheesy and pathetic romance novel, never use those adjectives like that. Ever. Especially towards Pearlcilina."

"Wouldn't want to sound like that," I grumbled, while deciding to change to subject away from Pearlcilina. Although Annabeth is like always right, I've learned to trust my instincts by constantly being in battle over the last few years. And right now, they were telling me that I'm right about Pearlcilina. I'd never let her know that, of course. A happy Annabeth is an unmauled Percy. "And Annabeth?"

"Yeah?" she replied, looking even more satisfied.

"Is Riptide a metaphor for the pen being mightier than the sword?"

She scrunched her eyebrows, seriously thinking. I love the way she looks when she does that.

Finally she answered, "I doubt that was the intention, but it's definitely possible. You should ask Chiron. Interesting observation, though."

"Oh and..."

"Hm?" Her gray eyes lit up at every question. I just couldn't help but smile.

"I know some monsters reform quicker than others, but do some reform right away?"

She immediately paled and looked as if she saw a ghost. "What do you mean?"

"I had to kill a Scythian Dracaenae today, but she reformed right after I killed her."

Annabeth now looked like she saw a ghost of a spider, and she started muttering something about doors.

"Look, Percy, I have to talk to you later. I'm really sorry. I'll talk about it tomorrow, alright? I just really have to talk to Chiron now."

"Um, it's okay. I understand."

Then she sprinted to the Big House.

A half hour later, I was in the middle working on my archery, which I really have to improve on. I was about to shoot an arrow when I suddenly felt a hot breath behind my neck. Being startled, I screamed and had the arrow go stray.

"Ahhhh!" a random centaur cried. My stray arrow hit him in the butt.

"Chiron wants you to give me a tour," the voice from behind me said, which belonged to Pearlcilina.

I couldn't wait to see the look on her face once she discovered that she had water powers! If she was a child of Poseidon, anyways. Still, I was completely convinced that she was one. That was why the canoe lake was the perfect last spot for the tour. The fresh, cool lake air breezed in our faces. I looked down at my bare feet, which were absorbing the toasty golden sand underneath. Then, I glanced up and saw a small wave roll on the surface of the glassy water.

"Do that," I told her as I pointed to it. Waves are pretty basic.

"Do what?" she asked, pretty frustrated.

"That!" I exclaimed as another swelled by. "A wave."

"Are you kidding me? No one can!"

I turned my head from the lake to her and asked, "Do you even know who my father is?"

She narrowed her sea-green eyes. "No, and I frankly don't care!" she snapped.

"Seriously? Think about all that has hap-"

"Neptune," she interrupted. "You are the son of Neptune."

"No, I am not the son of Neptune, and I never will be. He's Roman. You're thinking of Poseidon."

"Who cares. They're basically they same, anyways."

"I suppose they're pretty similar, but we're Greek. There are no Rom-"

"You honestly believe that?" she interrupted again. Her green eyes pierced into mine. "You think that us Greeks are the only ones out there? If Greek Mythology can exist, why not Roman Mythology? Or Egyptian? Or Chinese? Or Norse? Or Celtic? Or Japanese? Or Russian? Or-"

"Alright. I get the point."

She had a serious point, but it kind of gave me a headache. I never really thought about it- no one did. Could there be others camps out there, just like ours? My mind flashed back to the Labyrinth and the Titan battle. Didn't Janus and that fruit statue say that they were Roman? I always just assumed that they were delusional and wanted to be special snowflakes.

I obviously wasn't going to convince her to create a wave, so I gripped her arm and drug her into the lake with me.

"What the Hades are you doing?" she protested when the cool water was lapping around our hips.

"Hey, now you got it right!"

"Shut up! Seriously, what are you doing?"

"We're swimming! Come on, it's fun!"

"Why?" she hissed.

"Why not? You said you love to go party on the beach with your friends when I was giving you a tour-"

"Yeah! On the beach, with my friends!" she snapped.

I thought that she just wanted to be stubborn, so I pulled her in even more before she could further protest. We were at a drop off, so I was treading water, while the water was still up to her neck. Normally, this would be completely idiotic to do, but children of Poseidon are pretty good lifeguards.

"Isn't this great?" I exclaimed.

"No! Get me out of here!"

"Fine. Swim out yourself."

"NO!"

I suppose her leg slipped, because she started to splash around and scream like crazy.

"HELP!" she yelped at the top of her lungs. "I'M DROWNING!"

"It's okay! Just breathe underwater!"

"NO! YOU'RE CRAZY! SOMEONE! HELP!"

Right after she desperately cried that, she sunk to the bottom. I immediately dove to the bottom of the lake to retrieve her. She was still thrashing around with a thick trail of bubbles from her exhales above her. The water was cool and a very pretty clear blue. Not only that, but the sun danced everywhere. I would've stayed down here, if it weren't for Pearlcilina.

Eventually, we got out of the water, and I positioned her on the sand. I really hoped that I wouldn't have to do mouth-to-mouth. She began to cough and flitter her eyes open. She then gave me a slap that would have gave me a huge painful bruise for weeks if it weren't for my curse. I couldn't feel anything, of course, but it was really loud. I'm pretty sure it even echoed.

"YOU IDIOT! I hate you!" she shouted with scarlet rage.

"B-but I saved you!" I protested.

She yelled back, "Yeah, well, if you didn't almost drown me, you wouldn't have to do it in the first place!"

"Well, I saved you earlier today, yet you were nothing but a brat all day!" I retorted, which was true. I was really getting fed up with her.

She scrunched up her face and dug her hands into her hips. "Hm, I thought, perhaps, that almost drowning someone kinda out weighs being bratty! I guess I was wrong."

"Well, why didn't you just swim?"

"Because I can't, you idiot!"

Tears started streaming down her face. I really didn't know what to do- I messed up big time. She shakily stood up and started to slowly tread away.

I instantly stood up. "I-I'm sorry. I thought you were my twin," I muttered.

She stopped and turned around to face me. Then she rolled her red, watery eyes.

"Again, I'm sorry. I just get really lonely and desperate," I sighed. "The only sibling I have that won't bite my head off is Tyson, a cyclops. I love him and all, but he isn't always here. Besides, it's not the same as having a sibling you can rela-"

Pearlcilina looked like one of my face-eating siblings when she spat, "Seriously. Shut up. At least you weren't an only child."

"I actually was- just like the majority of the campers. And why is that even that big of a deal?"

She didn't reply and only gave me a hard, piercing glare, so I decided to continue.

"Were you raised in a dump?"

"EXCUSE ME?" she shouted while slapping me again.

"Sorry, nevermind. Don't take it personal- it's a child of the Big Three thing. Don't ask. By the way, are you adopted?"

For a while she violently stared at me in silence, but she finally grudgingly answered, "Yeah, they never told me, but it's extremely obvious. They're both Egyptian...and I'm not even remotely Egyptian. Why?"

"Um..."

We stood there in another silent moment until she blurted, "It's because you stupidly think that we're precious separated siblings, isn't it? Those kind of things only happen in movies and books, stupid!"

"Well," I gritted, really trying to hold my anger, "don't you want to know why I think we're twins, or at least related?"

She plopped herself down on the golden sand again and replied, "No, it's probably for really pathetic and feeble-minded reasons anyways."

I followed her action, while slipping my shoes back on. "Have you even compared how we look? We look quite similar," I replied, ignoring her answer.

"So? Lots of people have black hair."

"Well, um, yeah, but sea-green eyes and black hair? Besides, our faces look pretty similar. We're alike in other ways, too. Don't Perseus and Pearlcilina sound similar?"

"Don't you dare compare that terrible name with mine!" she unexpectedly complained.

Was she kidding? Why on Mount Olympus would anyone think her terrible name would be remotely as tolerable as Perseus, which is also an awful name?

"No, um, that was not my intention. Surgeon and sturgeon kinda sound the same, yet they're nothing alike in meaning," I explained. "Besides, is that even your real name?"

"They only sound alike if you're an idiot." She rolled her eyes again. "And, no, my name is so beautiful it has to be abridged. It's really Pearlcilina-Sofia-Ameythyst-Marie-Raven-Sapphire-Celestal-Destiny-Serenity-Sakura-Andromeda-Rachel-Helen-Hope."

I started to choke, which was all I could do to keep from laughing. "Sheesh! How many middle names do you have?" I blurted.

"Oh, no, that's all my first name. My adoptive parents were just extremely indecisive. Want to hear my even more beautiful middle name? It's Steve."

"Seriously?"

"No! It's just Pearlcilina, duh. You idiot! What else would it be? Just in case you can't figure it out, my middle isn't Steve either."

"Oh," I blushed. I wondered if she was also being sarcastic about thinking that her name was beautiful, but I afraid to ask, just in case she was being serious.

"Besides, what kind of child of Poseidon wouldn't be able to swim?" she continued.

"Thalia Grace, a daughter of Zeus, is sc-"

"We're talking about Poseidon, not Zeus, egghead!"

"Let me finish!" I barked. I cleared my throat. "Anyways, she's afraid of heights, so-"

"Are you saying that not being able to swim is a sign of having Poseidon as your father? Well, it's clear that you're not a child of Athena, then."

This was close to the last straw. "Quiet!" I shouted. "I can always drive you back into the lake!"

That seemed to do the trick.

"Anyways," I continued and cleared my throat, while gazing off into the crashing waves of the crystal lake, "why can't you swim? And why are you so obnoxious?"

She sighed. "How am I supposed to act? This Greek stuff...it's too much. All my life I was taught to believe that pegasi, satyrs, centaurs, cyclops, et cetera do not exist. Do you really expect me to be nonchalant and happy at the sudden realization that everything I was taught to not believe in is suddenly real? You're the one who brought me into this, so I guess I subconsciously despise you because of that. And I can't swim, because I never tried. The friends I had always would do these crazy life threatening dares. I, of course, have absolutely no problem with them for the most part, anyways. When I was a very little child, I stupidly jumped off a motor boat, thinking that my life jacket would save me. It obviously didn't, because it was too big for me, so it slipped off. I would've drowned if someone didn't rescue me. Ever since then, I have not been eager to do crazy stunts involving water. If I couldn't swim, I physically wouldn't be able to do their dares. Sure, I could take being teased by them, but I wouldn't be able to resist the temptation of those dares if I were able to do them," she calmly explained for once.

"Children of Poseidon can't drown. I could teach you," I sympathetically offered. Ever since I found out who my dad was, life without water just seemed so impossible and dull to me.

"Are you crazy? After today, no thanks," she frowned. "Besides, what if I'm not a child of Poseidon? I'm not even claimed yet."

She was right for once. After what just happened, no one with a functioning brain would let me be their swim coach.

"But," I began, "do you think we're related?"

"Well, duh. This is the Olympians we're talking about. We have to be related whether if my dad is Poseidon or not."