Hi guys! Did you like the mermaid theme from last chapter? I got the idea after seeing videos of mermaid shows on Facebook & TikTok. Now for this chapter, this theme is Party, which is an idea I got from the show Hey Arnold – Cool Party. I highly recommend you watch it because it's amazing. I hope you all like it!

And also, the appearance of Sonia & Manic from Sonic Underground is based on the designs by a Deviantart artist named DawnHedgehog555, so remember to check her work because it's amazing!

Laughter rang from both a blue hedgehog and light green hedgehog as they walked along the sidewalk, carrying their skateboards on either side in their signature colors. It was a sunny day outside, and the weekend had finally arrived. Deciding to take advantage of the nice weather, they both decided to head to the skatepark, where they competed against each other to see who was the most skilled.

"Seriously, Manic! You got spunk!" Sonic gave his brother a thumbs up.

"Thanks, man. You're not too shabby either," Manic winked.

"How were you able to pull off all those moves?"

"Practice, dude. And let's just say I saw how the other pros did it on TV."

"Still cool though!"

"Thanks."

They finally reached home, which is a modern 2 story house with a picket fence, lawn, and doormat. Wiping their feet, Sonic used his housekey to unlock the door, and opened it as he called out the house. "We're home!"

"I'm in the living room!" they heard their sister say.

Confused on why she's home early, Sonic & Manic placed their skateboards next to the door, removed their shoes, put on their house slippers, made sure the door is closed and locked, and hurried over to where their older sister is, who is sitting on the couch wearing her school uniform.

"Sis, I thought you were gonna be late because of a party you're going after your class was over?" Sonic questioned.

Sonia shrugged. "I did, but left early because it wasn't interesting."

"Let me guess? It was boring as hell?" Manic concluded.

"I wouldn't say boring."

"Alright, spill it. What happened?" Sonic sat next to her.

Sonia paused for a moment, as she saw Manic sitting on the other side next to her, and sighed as she opened her mouth to explain. "At school, one of my classmates told me I was invited to her party, which is for cool kids only. Unfortunately, some of my friends were on the geek list, which meant they weren't invited."

"Still don't get why you chose to go to that snobby rich school," Manic wrinkled his nose.

"Oh hush!" Sonia glared at him, then continued her story. "As I was saying, the others encouraged me to at least go see what the party is like. However, it wasn't that fun because there were only a few people, who are children of the richest families in this city. There was no music, the food wasn't appealing, and the decorations lacked in taste, so I left and came back home."

"Good thing you did, because there's a chance you would've died from boredom," Sonic patted her shoulder.

"Here lies Sonia, murdered by the most boring party she ever went to," Manic teased.

"H-Hey! Not all parties are boring!" Sonia pouted.

"I know, we'll chill," Sonic grinned. "Still bitter about the party though?"

"Not just me, but the rest of my classmates are. Right now, they're channeling their anger with sports, hobbies, or anything they do for extracurricular activities."

"Well then, I got an idea."

"Are we gonna TP the cool kids' houses!?" Manic happily grinned.

Sonic shook his head. "Nope! Even better! We'll throw a Geek Party!"

Sonia arched her eyebrow in confusion. "A Geek Party?"

"We'll hold it at the old warehouse located behind the docks, and everyone is invited."

"Awesome! Geek Party at the abandoned warehouse!" Manic whooped.

"Are we even allowed though!?" Sonia questioned.

Sonic winked. "I know a couple of people who can help us." He pulled his phone out from his pocket and started typing. "But first, we gotta spread the word out."

"I'll help!" Manic pulled his phone out from his pocket and rapidly started typing. "We'll also need to have some food, drinks, and music!"

Sonia sighs. "So much for staying home tonight."

Nighttime had arrived, and flashes of colorful lights came from the warehouse as the neon sign glowing brightly on the roof told everyone it's for Geeks only. Since everyone is invited, they didn't mind as they all entered the warehouse, ready to have some fun. Inside the warehouse is a ton of people, ranging from teens to young adults who heard about the party and wanted to come. Most of them the triplets recognized from their school, while some were friends or acquaintances of their classmates.

Tails had been appointed as the DJ, providing everyone with the best music they have along with making sure everything is working properly so there wouldn't be any complaints about the music. The speakers are great, his yellow headphones are secured around his neck, his laptop is in front of him, and everything else is in position.

If anyone dare try to mess with his equipment, they're not gonna like seeing him mad. They either face that or the wrath of Knuckles, which is something no one wants to endure at all. But in the meantime, its best to enjoy the music, have refreshments, dance with friends, and have the best night of your life.

"Hey blue!~ Nice party you have here!" Rouge called out to Sonic, as she did the waltz with Knuckles.

"Thanks, Rouge! And nice dance moves, Knuckles!" Sonic gave them a thumbs up.

"Tell her to release me! I do not dance!" Knuckles snarled.

"What about that time you once-

"I was intoxicated with punch!"

"Ciao!~" Rouge winked, taking Knuckles with her as they waltzed to a different area.

Sonia hurried over to Sonic, looking around. "I can't believe I'm saying this, but this party is magnificent! How were you able to pull it off!?"

"I asked for some help and a couple of friends I know owe me favors," Sonic answered.

"This party is legit! Everyone we know came!" Manic flipped his hair back. "Now what are we doing standing around for!? Let's dance!"

"An abandoned warehouse? Seriously?"

"I'm serious here! One of my guys mentioned its worth going to since the other party we went to almost killed us!"

"You mean the party for cool kids?"

"That place doesn't count because they don't know how to throw a wild party while the geeks are able to throw one here!"

Shadow rolled his eyes. "Tell me again why I was dragged here."

Scourge grinned evilly. "A buddy of mentioned seeing a yellow hedgehog at the party who strangely resembled your sister."

He suddenly felt his throat being squeezed, but not enough to block his airway. "H-Hey! Easy! I got the information from him, that's all!"

Shadow glared ferociously at the green hedgehog. "You better be lying! There's no way Maria would go to a party like this! She's still at home resting!"

"Then we can go inside and check to make sure if what he told me is true or not!"

"She better not be there, or someone is gonna die!" Shadow released him, stomping over to where the entrance is.

Scourge panted, snarling as he glared at the others. "How come you didn't stop him!? He could've killed me!"

Mephiles shrugged nonchalantly. "You must never anger a Robotnik."

"He's your crazy twin! Aren't you responsible for him!?"

"We are cousins. But I do agree with Shadow that it's not a good idea to joke about Maria coming to a huge party. She is still recovering from her condition."

"My buddy never lies about his information!"

"Then let's hope he values his life," Mephiles followed after Shadow.

Snarling, Scourge went after them, as they went through the entrance and were met with loud music, people having fun, food and drinks nearby, the DJ playing the best music there is, lights flashing, a giant disco globe spinning on the roof, furniture to sit or rest on, and many others whom they recognized from school.

"It seems to me we're not the only school who is here," Mephiles spotted his classmate Blaze, who is happily chatting with a pink hedgehog wearing a rose headband near the punch bowl.

"I don't see any geeks here! I see a bunch of hotties here!" Scourge smirked, eyeing a couple of girls sitting at the bar nearby.

"Shadow, the Jackal Squad are also here," Mephiles informed his cousin.

Shadow looked over to where his cousin is pointing at, seeing a couple of the Jackal Squad members dancing, while the rest are near the food stand chatting with each other. He noticed their leader Infinite is talking to a red wolf with glasses, and they seemed to be having a good time.

He shook his head and glanced at his cousin. "Forget about them. Tell me if you see Maria here or not."

Mephiles scanned the crowd, looking for the female yellow hedgehog whom he considers as his little sister. Then, his lime green eyes stopped at someone who was talking to Blaze and the pink hedgehog. It wasn't Maria, but a snowy white male hedgehog wearing a yellow shirt, blue jeans, and light blue sneakers.

"Do you see her, Mephiles?" Shadow asked.

"No, but I do see an adorable white hedgehog who needs someone to talk to. I'll be right back," Mephiles maneuvered his way through the crowd, avoid getting bumped or touched while ignoring Shadow's commands to come back here.

Seeing that Mephiles isn't helping, he then heard the DJ changing the song, switching to some sort of remix he does not know, but everyone else seemed to recognize it as they all danced to it. Scanning the crowd again, his crimson orbs stopped at a certain individual dancing to the song, and to Shadow, it appeared he's dancing seductively as he felt his body becoming warm.

The blue hedgehog wore a sleeveless black crop top with a yellow circle on it, giving him a nice view of his curvy figure and peach-colored belly. Blue jean shorts hugged his hips to cover his modesty, along with white socks, white gloves, and red sneakers. Besides a medallion necklace hung around his neck, he had a bit of light makeup on, and Shadow had never seen anyone with such perfect eyeliner that made his eyes pop out.

His long blue quills swished from side to side while moving with the rhythm, emerald-green eyes sparkling in delight at the music, and the way his body is moving with the music, watching his hips sway from side to side so it could match with the beat.

~Make your body wind like me~

~You will never find someone like me~

~Who can love you?~

~Nobody!~

~Hold you?~

~Nobody!~

~Make your body wind like me~

~You will never find someone like me!~

"How come no one told me that there would be a hot babe here!?" Scourge drooled, eyeing a light green hedgehog dancing with the blue hedgehog. "Fuck, that green vixen is sexier than everyone else!"

Shadow noticed the light green hedgehog Scourge was drooling over, who had strands of green quills framing his face and styled like a female's long hair, along with light brown eyes. He wore a black, sleeveless fishnet halter crop top to reveal his bare stomach and curvy figure, green mid-thigh army shorts, fishnet stockings, brown fingerless gloves, black choker with spikes on them, black bracelets with spikes on both wrists, and a 1 inch high heeled red and gray boots with white at the front. He even wore a medallion necklace like the blue hedgehog, light makeup, and 2 golden hoop earrings pierced his left ear.

~I wanna boom bang bang with your body, yo~

~We're gonna rough it up before we take it slow~

~Girl, lemme rock you, rock you like a rodeo~

~It's gonna be a bumpy ride~

They were both synchronizing with the music, not even realizing that the other dancers at the party were busy staring at them, mostly in awe at how they were able to move along with the music. Shadow didn't see Scourge's nose bleeding, nor heard him wolf whistle at his new prey. Shadow wasn't sure what he was doing here at the warehouse in the first place, but all he could think about is seeing that alluring blue hedgehog dancing to the music.

Then his eyes spotted a couple of female hedgehogs coming over to where the blue and light green hedgehogs were. One of them is a fuchsia pink hedgehog with shoulder-length hair, except the left bang is longer than the other, and her eyes are blue. She wore a white and pink dress with a heart belt wrapped around her waist, purple fingerless gloves, hot pink 2-inch-high heeled ankle boots, pink headband, medallion necklace, and light makeup on.

The other is a yellow hedgehog with long hair and two bangs framing her face, blue eyes, a sky-blue dress with long sleeves, blue headband, white gloves, blue bracelets on both wrists, white stockings, and blue and white knee-length boots. Shadow's eyes widened to see who she was, as he snarled viciously in anger.

"MARIA!"

His loud roar caused everyone to pause their movements, along with Tails stopping the music to see what's going on. The person who heard her name being called stiffened, glancing over to see a black hedgehog with red stripes wearing a black sweater, black ripped jean pants with a leather belt wrapped around his hips, black combat boots, white gloves, and golden rings on his wrists and ankles.

Gulping, she sheepishly waved at him. "H-Hello, Shadow."

Shadow angrily marched over to her, but was prevented when he saw the fuchsia hedgehog shielding her, along with the blue and green hedgehog holding their arms out to shield them from him. "Move aside!"

Sonic shook his head. "No can do. We don't know your relationship with her."

"Who are you, and how exactly do you know her?" Manic questioned, placing one hand on his hip.

"She's my sister, now let me through!" Shadow tried to push them away, but they firmly stood their ground. "Maria! Explain to me why you're here!?"

Maria fiddled with her fingers nervously, stepping away from her hiding spot. "I-I heard from my classmates on social media that there would be a Geek Party tonight, and everyone would be invited." She nervously looked at her brother. "Since you were gonna be at the Cool Party, I figured I could go to the Geek Party with Sonia."

"Which is me, though I had no idea you two were related," Sonia replied.

"It doesn't matter! You shouldn't even be at these types of parties! You're still recovering, Maria!" Shadow said in a strict tone.

"I know, but I really wanted to see what it would be like, brother."

"Does anyone at the house knew you were gonna be here!?"

"I-I did told grandfather I would be at a friend's house to study."

"So you lied to him!?"

"Shadow, please calm down. I just want to enjoy my first party here."

"Not at a warehouse, Maria! Remember your condition!"

"But I'm cured, Shadow. I don't have to stay indoors anymore."

"Not out here! You'll get sick!"

"Okay, that's enough!" Sonia yelled. "Look! I convinced Maria to come to the Geek Party with me, so be angry at me, not at her!"

"Then you should've realized she isn't allowed to come to these types of parties!" Shadow glared ferociously at her. "What the hell were you even thinking bringing her to an abandoned warehouse filled with hormonal teenagers and shit filled with drugs and alcohol!?"

"Hey! There are no drugs and alcohol at this Geek Party!" Sonic glared at him. "And don't you dare yell at my sister! She only wanted to show her more of what the outside world is like! Plus, she was gonna bring her back home before midnight!"

"Yeah, and we were gonna tag along so no one would bother them," Manic added, also glaring at Shadow. "So chill out, Ebony."

Shadow glared daggers at them, then closed his eyes as he took some deep breaths to calm himself. Once he felt calm enough, he opened them to gaze directly at his sister. "Maria, we're going home."

Maria pleaded with him. "But Shadow-

He placed his hand up to silence her. "Please do not argue with me. I don't want your condition to come back, so please come back home with me. Mephiles is here as well, and all 3 of us must return home before father wonders where we went."

Knowing how strict their father Black Doom is, Maria sadly nodded her head. "I understand, Shadow." She looked back at Sonia, gave her a hug, then did the same to Sonic & Manic. "I'm sorry, you guys. Thank you for letting me come to this wonderful party. I'm glad to be able to experience such a fun adventure."

"Hey no sweat," Sonic patted her shoulder. "Thanks for being my sister's friend."

"We're still inviting you over to our house for dinner next Friday night," Manic added. "We'll cook the best meals just for you."

"I'll have to get permission first, and thank you for the invitation," Maria sadly smiled at him, then hurried over to Shadow. "I'm ready, Shadow."

"Good," Shadow grabbed her hand, then turned his head to gaze at someone. "Mephiles, let's go! We're leaving!"

"Why must he spoil this moment," Mephiles grumbled, then hugged Silver. "I apologize, snowflake. I must leave immediately. I'll call you later and inform me when you have safely reached your residence."

He kissed Silver's cheek, who turned red as he hurried over to where his cousins are. Maria waved goodbye to Sonia, and left the warehouse with both her cousins walking on either side of her. As the door closed, the music had been turned back on, and everyone went back to dancing after the dramatic show is over.

However, Sonia wasn't in the mood, sniffing as she looked at the door where her friend just left. She felt her brothers hugging her on both ends, whispering comforting and soothing words to her as they stroked her hair or back, reassuring her that she'll be able to see Maria again.

Scourge, who witnessed the events unfolding, scratched the back of his head. "Is it too late to ask for your number, vixen?"

Manic gave him a heated glare. "How about you go outside and get some air instead?"

"Tomorrow it is!"

Shadow knocked on the door. "Maria, are you still resting?"

There was no answer, so he knocked again. "Maria, please talk to me! You've been in your room for 2 days!"

Turning the door handle, he realized it was unlocked and was able to open it, seeing a small figure hiding under the comforter on the bed. "Maria, I know you're under there."

Maria laid on her side, hugging her legs together and still dressed in her white nightgown while under the comforter. She refused to look at anyone, since she was still upset from what happened 2 days ago. It was her first time going to a party, and she wanted to experience what it's like to be a normal teenager, someone who never gets sick that much. But because of her condition, it was difficult to go out and socialize with her peers, not wanting her sickness to return, which is why Shadow & Mephiles are very protective of her.

She felt her bed being dipped, indicating someone is sitting near her, along with a hand resting on her arm. "Maria, you can't stay in the bed forever. Let's go outside to the backyard and get some fresh air."

"No thanks," Maria whispered.

Shadow's ears picked up on her words, as he sighed. "Staying cooped up in your room isn't healthy, sister. You'll get sick."

"I'm okay," she mumbled.

"Maria, I know you're still upset over what happened 2 days ago, but it was for your own good. Huge wild parties can worsen your condition, even if you had already recovered."

"I wasn't gonna stay there for that long," she whispered. "Sonia and her brothers were going to escort me home before curfew."

"Which is why I'm not allowing you to see Sonia while you're grounded. She's not a good role model for you."

"That's not true!" Maria sat up and turned around, frightening Shadow. "Sonia is very sweet and kind to me! She helped me discover things that I normally wouldn't get to experience because of my NIDS!"

Shadow frowned. "I'm glad you were able to make a friend, but taking you to that party was outrageous!"

"I convinced her to take me there!" Maria sniffed, gazing down at her lap. "I wanted to feel like a normal teenager, someone who wants to have fun and never gets sick."

His eyes softened, placing his arm around her as he pulled her close in a side hug. "Maria, you'll be able to experience all the fun stuff as a normal teenager. However, you must never forget that you just recovered from your NIDS, and I'm scared that you could get sick again. So please, just try to be more careful."

"Then please don't keep me away from Sonia. She's good to me."

"As long as she doesn't take you to anything extreme, then I'll allow it."

"Thank you, big brother."

"You're welcome. Now, go ahead and freshen yourself up. You look like you really need it."

"I'll do that, Shadow."

At night

Shadow's ears picked up on the sounds of something hitting his glass window. Hurrying over to see what's going on, he opened the window and looked around, then his eyes widened as he spotted the person responsible for it. "You!?"

Sonic waved at him. "Yo! Good thing I found the right room!"

"What are you doing at my house!?"

"Come down here, and I'll tell you the reason why!"

"And if I don't!?"

"Then I'll haunt you in your dreams for the rest of your life!"

"That's impossible!"

"I have my ways!"

Shadow growled, seeing a smirk stretch on that cute hedgehog's lips. Wait, did he just call him cute!? Okay, now he needs to let his mind rest. But first, figure out what he's here for. Looking around to make sure there is no one watching them, along with making sure the rest of his family are sleeping, he carefully climbed down from his window using some vines attached to the wall, thankful that they're not loose.

As he hopped off the vines and landed on his feet, he stood up and folded his arms. "I'm here now. Tell me why you're here?"

Sonic mirrored his actions. "Let my sister Sonia continue to be your sister Maria's best friend."

Shadow arched his eyebrow. "Come again?"

"You heard me. Let our sisters continue to see each other. Sonia loves spending time with Maria."

"Why?"

"I've never seen Sonia so happy before. She always tell us about what Maria did, what she said, the cutest outfits she wore, and everything else she rambles on related to your sister," Sonic's lips twitched as he smiled. "Those two have a healthy friendship, and I want them to be happy with each other. You gotta allow Maria to see Sonia again."

Shadow sighs. "I told Maria I'll allow her to see Sonia as long as she never goes anywhere dangerous."

"The Geek Party wasn't even dangerous."

"It was a wild rave party at an abandoned warehouse filled with hormonal teenagers, adults, and alcohol."

"There's no alcohol in punch."

"Maria's safety comes first."

Sonic placed his hands up in surrender. "I get it. You're protective of your sister because you don't want anyone to take advantage of her kindness. I feel the same way with my sister, and I won't hesitate to commit a felony if anyone dare mess with her."

"Then you understand why I acted that way yesterday."

"I know. Sonia told me about how your sister Maria once had NIDS, but is now cured and made a full recovery. You just don't want her to get sick again, do you?"

"No I do not."

"Then let her be able to experience life as a normal teenager. It doesn't have to be the dangerous kind, just the fun stuff like going to the movies, shopping at the malls, skateboard at the park, go to an amusement park, or do anything she's interested in."

Shadow thought about what he said for a minute, then slowly nodded his head. "I suppose you're right. Maria does like going to the city where she can shop at the bookstore, go to the museum, get some ice cream, or anything she always wanted to try."

Sonic smiled, placing both hands on his hips. "There we go! So you'll allow our sisters to remain friends?"

"Only if Sonia promises to never take Maria to any wild parties, even if my sister begs her or tries to use the puppy dog look. Maria is not allowed to go to those parties unless I'm with her."

"Great! Now Sonia can finally take Maria to the planetarium as promised!"

Shadow arched his eyebrow. "What planetarium?"

Sonic playfully stuck his tongue out. "Nothing to know, hot stuff."

A light blush spread across his cheeks, as Shadow growled at him. "My name is Shadow, not hot stuff."

"I know. Maria already told us about you," Sonic grinned. "My name is Sonic, the blue hedgehog you stared at from the Geek Party 2 days ago."

Shadow stiffened. "I-I do not know what you're talking about."

"Dude, I knew you were staring at me dancing from the Geek Party. Were you entranced at how well I can dance to the music?"

"I-I was glancing! I did not stare at you!"

Sonic winked. "If you wanna see more of my hips moving, then we can go to the club next weekend. I'll even wear a red crop top so you can get a good view of my figure."

"I'm not a pervert, you imbecile!" Shadow turned red, glaring daggers at him.

"Then why do I see a tent forming?~"

His answer is getting chased by an angry, blushing black hedgehog, who yelled curse words at him while Sonic sped away laughing. It's obvious Shadow wanted to get to know Sonic and get close to him, and Sonic wanted to learn more about Shadow. In the meantime, he'll start by teasing the grumpy hedgehog until he makes the first move. Plus, he always thought Maria's brother is pretty cute.

There we go! Besides Sonadow, I added a bit of Mephilver, Blazamy, Infidget, Manourge, and some Sonaria (Sonia X Maria). Remember to review and comment, and feel free to add any more ideas for the one-shots!