AN: Yo! I hope you enjoy this story. Just a heads-up: it's set in a completely alternate universe. The main characters will be the original trio—Percy, Annabeth, and Grover—along with a new original character. While I've read the original books, I wanted to take a different direction, so I'm basing this story on the TV series. If you're not a fan of the TV adaptation, this might not be for you. However, if you love the show and want a well-written story featuring those versions of the characters, you're in for a treat. This book will have almost no connection to the original plot of the books, so please don't send me messages about what is or isn't canon.

Prologue

Who Invited the Siren?

I always imagined that when I turned sixteen, I'd somehow end up with a car. Or, more realistically, I thought I'd fill several pickle jars with cash, and on my 16th birthday, my mom would take me to a shady dealership. There, we'd buy a half-functioning vehicle that I would name, love, and cherish like family. If I were a normal kid, that would be the expectation. But I'm anything but normal. Four years ago, I discovered I was a half-blood, a demigod—and not just any demigod, but a forbidden one. Why forbidden? Because my dad is Poseidon, the god of the sea, earthquakes, and horses, and one of the Big Three. Yeah, the same Big Three (Hades, Zeus, and Poseidon) who swore off having kids. Oops. So, when I found out I was Poseidon's son, it wasn't exactly a Hallmark moment. Then, just to keep things interesting, on my sixteenth birthday, Poseidon decided to gift me a massive pirate ship. Because nothing says "happy birthday, forbidden child" like a vessel straight out of Treasure Island.

Okay, so it's not actually a pirate ship. My father called it a Friggan—a Fritadda—or was it a Frigate? Whatever. What I do know is that it's a replica of a 1780s Spanish battleship. Imagine this: towering masts, billowing sails, and enough cannons to make you feel like you're starring in the next Pirates of the Caribbean movie. It has creaky wooden decks that make you question its seaworthiness and ornate carvings that scream, "I belong in a museum, not the open sea." The whole thing is absurdly grandiose, with more gold trim than a rapper's grill. It's like the ship is trying way too hard to prove it's from the 18th century. I mean, really, who needs that many ropes?

You're probably thinking I'm a spoiled, ungrateful brat, and maybe you're not completely wrong. But think about it—my dad's a god. How hard would it be for him to get me a Lamborghini or a Tesla?

"Your majesty, your coming-of-age ceremony dinner is about to be served. Please make your way to the dining hall."The voice of a sea guard immediately drew my head to the front of my living quarters. I gave him a thumbs up, and he slipped his head and trident out of the doorway, sliding the stone door shut behind him.

Oh, I should probably mention that I'm currently staying in my father's oceanic kingdom. As the summer session at Camp Half-Blood came to a close, one of the camp's lake nymphs told me I was expected to attend a coming-of-age ceremony at the bottom of the ocean. Naturally, I was skeptical. If my dad wanted me to swim to the ocean floor, he could have told me himself. But we all know that's not how the gods operate. Instead, my mom confirmed the water nymph's message, explaining that she had agreed with my father to let me stay with him, but only for a few days. I think It's still hard for her to accept that I can breathe underwater or that my body won't implode at deep depths.

As for my father's kingdom, it's probably the eighth wonder of the world. There are towering coral spires that make the Empire State Building look like a Lego piece, shimmering schools of fish weaving through intricate arches, and palaces carved from mother-of-pearl that glisten with every imaginable hue.Massive sea horses the size of thoroughbreds float by as if it's the most normal thing in the world. Giant clams serve as throne chairs, opening and closing with a flourish. The whole place is lit by bioluminescent algae, casting an ethereal glow that makes you feel like you're in a dream. And the gardens—fields of waving kelp, sea anemones that sway like they're performing a synchronized dance, and starfish that lounge around like they own the place.

My room—or my "living quarters" as the castle attendants call it—is well, how can I explain this? Imagine a bedroom that looks like it belongs to an underwater Disney princess. There are arching windows framing views of colorful coral reefs and schools of fish swimming by as if they're auditioning for a nature documentary. The bed itself is like something out of a dream, with silky sheets and pillows so fluffy they might as well be clouds.The walls are adorned with intricate carvings and there's more sparkle than a blinged-out jewelry store. Lamps made of glowing pearls light up the room, casting a soft, magical glow. Everywhere you look, there are vibrant sea plants and ornate decorations.

Slowly, I lifted myself to my feet, deciding it would be better not to keep the people of my dad's sea kingdom waiting. Their culture and customs were hard to understand—almost everything I said or did seemed to offend some random bystander. Son of Poseidon or not, it didn't change the fact that I was first and foremost a land dweller. It felt like everything I did here was offensive. I mean, I couldn't even wave without someone looking at me like I'd committed a crime.

I trudged through the palace corridors, which were as lavish as you'd expect for a sea god's home. The hallways were lined with towering marble columns and adorned with shimmering mother-of-pearl inlays that caught the filtered sunlight from above, creating a dazzling, almost hypnotic effect on the walls and floors. I swore, even the fish swimming outside the windows seemed to be judging me with their unblinking eyes.

As I navigated through this underwater labyrinth, I passed open rooms filled with opulent furnishings. Each room was a masterpiece, with vibrant sea plants and intricate coral sculptures that seemed to whisper secrets of the deep. The floors were tiled with gleaming aquamarine and jade, and the ceilings—man, the ceilings!—were high and arched, covered in mosaics depicting epic sea battles and legendary creatures. It was like walking through the pages of an ancient myth, except with more humidity and the constant sound of water.

Finally, I reached the dining hall. If you think the rest of the palace was extravagant, this place took it to a whole new level. The ceiling was made of crystal-clear glass, offering an uninterrupted view of the ocean above. Fish of every imaginable color swam by, accompanied by the occasional turtle and, once, a very curious octopus that pressed its tentacles against the glass as if it were trying to get a better look at the festivities below.The hall was decked out for my coming-of-age ceremony in a style that could only be described as "underwater chic." Tables draped in luxurious fabrics were scattered throughout the room, each one adorned with centerpieces made of glowing jellyfish lanterns and delicately arranged seaweed garlands. The atmosphere was both magical and slightly surreal, like a party scene from an aquatic legend.

The citizens of the kingdom were scattered around the hall, dressed in bright, interesting clothing that made them look like they'd just stepped out of a very fashionable aquarium. Some were eating exotic delicacies that I couldn't even begin to identify—seriously, one dish looked like it was still moving—while others were dancing to music played by an ensemble of sea creature musicians. Their instruments, made from shells and coral, produced melodies that were hauntingly beautiful and unlike anything I'd ever heard on land.It was a scene of laughter, clinking glasses, and vibrant colors, with the occasional dolphin leaping up to perform a mid-air trick for the guests. It was all so ridiculously excessive and otherworldly. And yet, amidst all this splendor, I couldn't help but think: I'd still trade this entire royal experience for a decent car.

"Percy, my son, so glad you could finally join your party. The guests were beginning to think you ran off with your new ship to return back to the shore."I was slightly taken aback by my father's presence. He placed a heavy hand on my shoulder. He was wearing a dark blue tuxedo with light green accents, the kind of outfit that screamed "I'm the god of the sea and I have style." The suit was tailored to perfection, with intricate wave patterns embroidered along the cuffs and a trident-shaped brooch pinned to his lapel.

"It's definitely tempting," I replied.Poseidon chuckled, his deep voice resonating through the hall.

"So, how do you feel about staying here? Is it everything you imagined?"I hesitated for a moment, searching for the right words.

"Everything is beautiful and interesting, but I'm not fully used to it. It could potentially be a second home one day, but right now, it's still pretty overwhelming."Poseidon nodded thoughtfully.

"And why didn't you invite your girlfriend, Annabeth? I'm sure she would've enjoyed this as well."I felt my face flush with embarrassment.

"Wha-What? Um, no. I don't have a girlfriend, Dad. Annabeth and I are just friends."Poseidon raised an eyebrow, clearly amused. I could feel my cheeks burning. Annabeth. The girl who was always there, who had saved my life countless times, and who I sometimes thought about a little too often. We were just friends, but there were moments that made me wonder if there could be something more. The idea of it scared me a bit. I mean, what if she didn't feel the same way? What if I messed up our friendship?Desperate to change the subject, I blurted out the first thing that came to mind. "So, Dad, what do you think about my suit?"His amused expression softened into a smile.

"You look nice tonight, Percy."

I glanced down at my outfit, a sharp black suit with a deep ocean-blue tie. It was the nicest thing I had ever worn, and I had to admit, I cleaned up pretty well. "Thanks, Dad. You don't look too bad yourself."He chuckled and I could see the vibrations of his timbre ripple in little waves though the water. "So, what's in store for the ceremony?" I asked, hoping to steer the conversation as far away from the topic of Annabeth as possible.

Poseidon's eyes twinkled with mystery.

"Oh, you'll see soon enough. Just enjoy the evening for now."

Great, more vague god answers. Just what I needed. Internally, I rolled my eyes but couldn't help feeling a bit excited. "Well, Dad," I said, breaking the silence, "if tonight's ceremony involves any crazy god stuff, just give me a heads up, okay?"

He laughed, patting me on the back. "Don't worry, Percy. You'll do just fine."

As we walked through the hall, the citizens of the kingdom continued to eat, dance, and celebrate. The whole scene was a bizarre mix of whimsy and elegance, and I couldn't help but feel a bit out of place. But at the same time, there was something oddly charming about it all. Even if I did occasionally feel like a fish out of water—pun intended—I had to admit, it wasn't so bad. Maybe, just maybe, I could get used to this.

The evening drew on, and I started to become less uncomfortable with my surroundings. If you ask me, I think it had something to do with the drinks they were serving. Well, I wouldn't actually call them drinks. This may or may not come as a shock to you, but deep-sea dwellers don't drink liquids. Shocking, right? I mean, who would have thought. Instead, they suck air out of these large colorful bubbles.

The first one I took for myself was a silvery chrome color. I stared at it, not sure how to consume it. The server, who had been carrying the bubbles in a large bowl, prompted me to bring the bubble to my lips and suck in. The moment I did, my mouth was immediately filled with air that tasted like the most concentrated form of 7-Up. It caused the hair on the back of my neck to stand on end, and if I hadn't already been underwater, I guarantee my eyes would have begun to water. The fizzy feeling went straight to my head, and I knew in that moment I was totally addicted.

Seven bubbles later, and I was definitely taking my role as the "birthday boy" very seriously. Suddenly, I was the life of the party, joining in on random conversations and thanking every visitor for participating in the festivities. I caught my father watching me as I paraded around the dining hall like a social butterfly. He seemed delighted that I was coming out of my shell, and for some reason, that made me feel proud.

One of my new merman friends had explained earlier that the sea kingdom, and sea world in general, had a vast repertoire of musical artists and insisted I request a song that would get everyone dancing on the dance floor. It was called the Trench Trot, and I immediately speculated it would be some kind of line dance. My speculation was obviously correct. It was like a flash mob the way everyone in the hall stopped what they were doing to bust a move.The music started with a deep, rhythmic beat that resonated through the water, accompanied by a melody that sounded like a blend of whale songs and electric guitar riffs.

It was strangely hypnotic. The dance floor was illuminated by bioluminescent algae, casting a mesmerizing glow over the swaying sea plants and colorful coral decorations. Everyone seemed to be in sync, their bodies moving gracefully with the currents, like a well-rehearsed underwater ballet.I had absolutely no idea how to do the dance, and it took the blessed patience of several ocean nymphs and a large sea lion to teach me how to rhythmically propel myself in the water.

Eventually, I caught on. Once I did, I was thrusting my hips like a trainee in a K-pop boy band whose whole career banked on their debut on a cheesy variety show.After the Trench Trot, the dance floor became everyone's space to socialize. I felt very much like I was in a club, which was cool considering I was only 16 and, on land in America, most clubs require you to be 21. The music transitioned to a faster tempo, and the dancers morphed into a kaleidoscope of colors and shapes, their movements fluid and expressive. Laughter and cheers echoed through the hall, mingling with the pulsating beats of the music.

In my opinion, the sea creatures were the most impressive dancers—dolphins twirled gracefully above us, jellyfish pulsated with the rhythm, and even a couple of octopuses showed off their surprisingly impressive dance moves. I couldn't control the grin on my face. I felt I was finally in my element, quite literally, and it felt like I was part of something magical.

While I was enjoying the spectacle, a stunning mermaid glided toward me. Her long, shimmering hair cascaded down her back, and her piercing hazel eyes seemed to flicker with flames. She moved with an alluring grace, every gesture designed to mesmerize.

For a moment, I truly believed she was a daughter of Aphrodite, so enchanting was her beauty."Hello, Percy," she said, her voice like a melody that sent shivers down my spine. "Would you care to dance?"A slow, sultry song began to play, and I felt an irresistible pull toward her.

"Sure, I'd love to," I replied, unable to tear my eyes away from her. Her presence was intoxicating, and as we danced, her proximity and the intensity of her gaze made my heart race. Despite my growing infatuation, thoughts of Annabeth flashed through my mind. Annabeth, with her beautiful brown skin, curly hair, and petite yet strong frame. She was so different—pixie-like and graceful, yet undeniably stunning.

But this mermaid... she was something else entirely. The room seemed to dim, and the only thing I could focus on was her. "You dance well," she whispered, leaning in closer. "But I know you can do more than just dance, Percy. You have a great destiny."Her words sent a shiver down my spine.

"Thanks," I said, trying to keep my composure. "What's your name?"

"Names are just a formality," she replied with a mysterious smile. "But you can call me Seraphina."

"Seraphina," I repeated, feeling the name roll off my tongue. "That's beautiful."

"Not as beautiful as what lies ahead for you," she said, her voice dripping with promise. "I can show you wonders beyond your imagination, Percy. All you have to do is trust me."The air seemed thicker, and a strange fog began to cloud my mind.

"What kind of wonders?" I asked, feeling both curious and uneasy.

"Come with me to your ship," she whispered, her eyes glowing with an intense light. "We can sail to a place where you will find true power and fulfillment. Head north, toward the coldest waters. There, you will discover your true potential."Her words were like a siren's call, and despite the growing sense of wrongness, I found myself nodding.

"But what about my friends, my father, my coming of age ceremony?" I asked, trying to fight the spell she was weaving.

"They will understand," Seraphina said, her voice soft and persuasive. "This is your destiny."A part of me screamed that something was wrong, that this was a trap, but the allure of her promise was too strong. I tried to shake off the feeling of betrayal toward Annabeth, telling myself that we hadn't defined anything yet. This was just an adventure, right?Moving through the crowd, I felt my thoughts becoming hazier.

"Seraphina, what are you doing to me?" I asked, my voice weak."Shh, Percy," she whispered, her smile both comforting and terrifying. "Just trust me."

My vision blurred, and I realized too late that I was falling victim to her curse. As darkness overtook me, the last thing I saw was her triumphant smile. My mind went blank, and I slipped into unconsciousness, completely under her spell.

AN: leave a review!