A/N: Turning this into a full-length semi-plotted fic by popular demand... Similarly to Extra Credit, it will be unbeta'd, have reasonably short chapters, and updated on a semi-random basis. This is a prologue. The next chapter will pick up on their first day of high school.
Part of this chapter is the drabble that inspired this ("Best Friends"), with a few changes made. In order, Klaroline are four, seven, nine, and thirteen.
For Cassie, Gail, and Bex. Thank you to Giulia for part of the cover. You deserve all the spare rainbows.
Enjoy!
-Angie

"Hey, Liz," Esther said tiredly on the other end of the line.

"Everything okay?" Liz asked immediately, swapping her phone from one ear to the other as she bent down to pick up a Barbie shoe and throw it back in one of the plastic buckets they used for toys (those things were painful when stepped on).

"Yes, mostly. I was just wondering if you'd be willing to take Niklaus for the afternoon? I know it's short notice, but-"

"Of course. I'd be happy to. I'm sure that Caroline will be thrilled."

Esther laughed. "Both of them, more likely. I'm so glad that they get along. I'll come by in around an hour? Don't worry, I'll get him lunch before we come."

"Sounds good. I'll see you soon."

Liz sighed, hanging up the phone and turning to Caroline, who was peacefully stacking wooden blocks. "Caroline, Nik's coming over later."

Caroline looked up, her face immediately brightening. "Really?"

"Yes. Why don't you go get dressed and brush your hair."

"Okay," her daughter said, shooting up on her feet and speeding down the hall almost before the end of Liz's sentence was out of her mouth.

Liz allowed herself to smile slightly at her daughter's eagerness to see her friend and sat down on the couch with her laptop.

She heard the pitter-patter of Caroline's light footsteps as she came back into the living room, sitting down where she'd been before, concentrating on her work until she heard the beep of a phone.

"Caroline, put that down!" Liz ordered from the other side of the living room.

Caroline pouted but obligingly dropped the phone and sat down. "When are they coming?"

"Twenty minutes."

"No," Caroline said, grabbing a few blocks from the basket in the corner and starting to stack them.

Liz sighed. Caroline was obnoxious, precocious, and energetic, which was, in her humble opinion, one of the worst combinations of traits for four-year-olds. She had a short attention span and was very rigid about things that she wanted, and was always running around doing something.

She couldn't wait for Esther to arrive with her son Niklaus (though the kids all called him Nik because of the collective problem they seemed to have of pronouncing 'Klaus') so that Caroline would calm down a bit. He was easy-going and quiet, a direct contrast to Caroline's excitable nature, but while Caroline threw tantrums every now and then that were more for show than anything, Klaus's tantrums were worse, though he didn't have them often.

The doorbell rang and Caroline clambered to her feet, looking at her mother expectantly and following her to the door. "Esther, it's good to see you."

"Hi, Liz," Esther said tiredly, moving aside so Klaus could walk into the house,

"How are you?"

"It's been one of those weeks, but I'm all right," Esther said, rubbing her very pregnant belly lightly. "This one wants out, and frankly I agree. It's a good thing that Elijah and Finn aren't a huge handful or I wouldn't know what to do. I only have to run around for Klaus and Kol."

"Can I get you anything?"

Esther smiled. "No, thank you. I should go. I can't leave Mikael with Kol by himself for more than half an hour before he's hiding in his office."

"Would you like me to drop off Nik so you don't have to drive over?"

"Yes, that would great actually. Is four all right? That way I can already have picked up Elijah and Finn."

"I can do that."

Esther gave her a grateful look. "Thank you."

"Of course! I'll see you then."

Liz walked Esther out and then turned to go back to the living room to finish the report she was filing and keep an eye on Klaus and Caroline.

"But it would look so much prettier if each floor was a different color," Caroline was saying as she carefully positioned a red block on the tower.

Klaus just shrugged and obligingly put down the blue block he'd been about to place on the tower and picking up a red one.

They continued that way for awhile until they were out of blocks and had built a rather unstable but tall block tower.

"Mommy we're done. Come see."

"It's really great, guys!" Liz said tiredly, taking one look at it before turning back to her work.

"Can we do play-doh?" Caroline asked.

"Why don't you let Nik have a turn picking."

"But Nik likes play-doh."

"Well, that doesn't mean that he wants to play it right now. Nik, do you want to pick something to do?" Liz said kindly, determined to help Caroline learn the concept of taking turns.

"Play-doh," he said quietly, edging slightly towards the small table on the side of the room, which was usually where they played.

"See?" Caroline asked irritably in an I-told-you-so tone.

"Yes, Caroline, I see," Liz said dryly, wondering if Klaus was just doing what Caroline wanted to do, but deciding not to pursue the subject.

She set them up with the different colors on the table in the corner and then returned to work, listening with half an ear to the conversation.

"What are you making?" Klaus asked, his hands already separating the play-doh into neat circles.

"A puppy. What are you making?"

"I don't know yet."

They worked in silence for a few minutes before Caroline made a frustrated sound. "I can't make the legs work."

Klaus glanced at her play-doh creation and smiled slightly before grabbing it.

"Hey!"

"Wait. I'll fix it," he said, pulling the tiny sticks Caroline had made into legs off the 'dog' and squishing them into smaller pillars, reattaching them carefully and handing it back. "Now it stands up."

"Thanks," Caroline said happily, setting it on the table and looking at it for a few seconds before balling it back up to make something else.

Klaus just rolled his eyes at her Caroline-ish behavior (he was used to it by now) and continued on whatever he was doing.

Caroline had made a flower, a cloud, and a butterfly by the time Klaus had finished his elephant (and Liz was rather impressed by how much it resembled one, taking in Klaus's age), and then Liz had them clean up, which Caroline did while Klaus sat there and watched. "Nik, do you want to help Caroline clean up?"

"It's okay, Mommy. Nik did mostly the blocks."

"Nik cleaned up almost all the blocks," Liz corrected automatically, before realizing that Caroline was packing in the last jar of play-doh and Klaus was just sitting there, smiling slightly.

"Can we paint?" Klaus asked quietly after Caroline had pounded the cap on the jar with her palm.

Liz checked the clock and was saw that they had about two and a half hours left.

"Yes. I'll get everything out."

Five minutes later, the two of them were set up with heavy paper and child-safe paint, which Klaus immediately stuck his hand in and started brushing across his paper. Caroline wrinkled her nose at the paint and Liz put a box of crayons in front of her daughter, who immediately began coloring.

"All done," Caroline said about fifteen minutes later, holding up her picture.

It had two stick figures, one with blonde hair and a pink body and the other with tan hair and a green body. "This is you," she said unnecessarily pointing to Klaus.

He smiled and returned to his finger painting, which was mostly just streaks of paint on a paper rather than any actual shape.

Caroline grabbed another paper and started drawing again, and a few minutes later she proudly showed Liz a picture of a person under a rainbow, her messy childlike handwriting spelling out the title and her name with a happy face underneath. Klaus pushed away the paper he'd been painting on a few seconds later and was about to get up from the table by the time Liz realized that he was done (and covered in paint).

"Wait, Nik. Let's get you cleaned up."

He shrugged and started walking past Caroline with a mischievous smirk on his face, and pressed his paint-covered hand against her dress.

"Hey! You got paint on my dress."

Klaus just gave her an innocent smile and started backing up towards the bathroom.

"No. You can't ruin my dress. Meanie."

"I did though."

Caroline's eyes filled with tears. "I like this dress. It's pretty and you ruined it."

"It's okay, honey. It'll wash out," Liz said quickly, trying to nip the coming tantrum in the bud.

"Nik was mean," Caroline hiccuped, and Liz turned to ask Klaus to apologize when he beat her to it.

"Sorry," he muttered quietly before bolting towards the bathroom.

"Whatever." Caroline mumbled.

"Can you put the crayons away, Caroline?"

She pouted but walked over to do as she was told while Liz made sure that Klaus didn't have anymore wet paint all over him.

"Can we watch something?" he asked when they returned to the living room.

"Sure. What do you want to watch?" Liz asked, heading towards the television.

"Aladdin," Caroline said decisively at the same time as Klaus voted for The Lion King.

"Well, you'll have to decide."

"Aladdin is fine," Klaus said, and Liz sighed exasperatedly at his immediate agreement with her daughter.

It was always interesting to watch the two interact because they often disagreed on things, but seemed to immediately realize that they disagreed and one of them would cave, though it was Caroline who more often than not got her way.

She had brought Caroline over to the Mikaelson's to play before, and Klaus would argue until the cows came home with his siblings about things he wanted to do, not backing down for a second, but when Caroline wanted something, usually she got it.

She hadn't known it was possible for a child to be spoiled by another child until Caroline and Klaus became friends. Honestly, she often wondered if they'd grow up to be one of those rare best friend pairs that ended up dating and getting married, but she'd shake herself and remember that the odds weren't in their favor. It was nice to think about though, especially since Esther was one of her best friends.

"Happy Birthday, Nik," Caroline crowed happily, attacking Klaus with a hug.

"Thanks," he said quietly, hugging her back quickly before stepping back.

Caroline pouted at his luke-warm greeting, but trotted off after him into the kitchen where the rest of his siblings were, hopping up on the chair at the kitchen table and gratefully accepting the juice that Elijah handed her. "Thanks."

"You're quite welcome," he said stiffly, making her stifle a giggle.

Elijah was ten and, in her opinion, he tried too hard to be a grown-up. He insisted on wearing polo shirts and khaki pants all the time, which she couldn't understand for the life of her. Why would anyone choose to be in stuffy clothes? "Stefan and Marcel should be here in a few minutes," Esther said from the counter, where she was preparing sandwiches.

"Okay, Mum."

"What are we doing today, Nik?" Caroline asked, excited to do party activities.

"I want to play Operation," he said quietly.

"Can I play?" Rebekah asked.

"Yes," Caroline said happily at the same time as Klaus let out a sharp denial.

Rebekah's eyes filled with tears. "You never let me play with you, Nik! Ever. Why are you so mean?"

"Niklaus, let your sister play."

"No, Mum. It's my birthday. I don't want her to play."

"You're just worried I'll beat you," Rebekah said, her lower lip still trembling.

"Am not!"

"Are too!"

"Am not!"

"I think we should let her play with us, Nik," Caroline said as she walked to the cabinet, standing slightly precariously on her toes to reach the cardboard box containing the game.

"Okay. Fine," Klaus immediately capitulated, making Caroline smile.

She brought back the box and they moved to sit on the floor, the tweezers clutched carefully in Klaus's hand. Klaus was absurdly good at games that required fine motor skills-probably something that was a product of his obsession with painting-and Caroline pouted as he efficiently picked out half the bones before she and Rebekah had gotten one. "This is no fun," Rebekah said.

"You wanted to play," Klaus reminded her.

The doorbell rang, and a few moments later Stefan walked into the room, thrusting a neatly-wrapped present into Klaus's hands and sitting down in between him and Caroline. "Happy Birthday."

"Thank you."

Marcel got there a few minutes later, and they decided to switch to Uno.

"Wild Draw Four," Caroline announced proudly, slapping the card down, making Stefan groan as he picked up four cards. "I pick yellow."

She saw Klaus smirk out of the corner of her eye and she shot him a bright smile. Rebekah and Marcel took their turns and then Klaus put down a card, Caroline almost immediately playing one of her own on top. "Uno," she said happily.

Klaus ended up winning, and they were about to play again when Esther announced that it was time for cake. They sang Happy Birthday, ate cake, and then Klaus opened his presents. Stefan got him a set of action figures, and Marcel got him a large box of Pirate Legos. At the signal of Esther's raised eyebrow, he thanked them both politely before opening Caroline's present. She'd dragged her mother to the toy store and looked around for forty-five minutes for the perfect painting set.

He smiled brightly at her, immediately unwrapping it to look through the watercolor book, already completely engrossed, and Esther graced Caroline with one of her rare genuine smiles. "Thank you," he said quietly.

"You're welcome."

"Ugh. Tyler, you're so mean!"

"I'm not mean. It's true. You're a brat."

"I am not a brat," Caroline said, her voice low and slightly dangerous.

"Yes, you are. You're a bratty tattle-tale," Tyler said accusingly.

"Shut it, Tyler," Klaus said irritably from the other side of the lunch table after swallowing a bite of his sandwich.

"Or what?"

Klaus shrugged. "Or you're embarrassing yourself."

"Am not."

"Well, when you say that about her, you're lying to everyone around you, and that's embarrassing," Klaus said, shrugging.

"You're embarrassing."

Klaus just rolled his eyes, taking another bite of his sandwich.

"Go away, Tyler," Caroline ordered.

"Fine," Tyler said rather petulantly, stalking off.

"Thanks, Nik," Caroline said, smiling at him.

"For what?"

"Standing up for me."

"Always. And anyway, you wouldn't have needed it if he wasn't such a prick."

"Nik!" Caroline screeched. "That's a bad word."

Klaus rolled his eyes. "And?"

"And you shouldn't say it."

"Why not?"

"Because...because it's bad."

Klaus's lips twitched. "All right. If you say so."

"I do say so," Caroline said haughtily, suppressing a smile when he ducked his head, grinning and taking another bite of his sandwich.

"Guess what, Caroline?" Elena asked, giggling uncontrollably.

"What?"

"Tatia likes Klaus."

Caroline resisted the urge to snort. Elena, Tatia, and Katherine were triplets, and the three of them were as gorgeous as they were irritating. "Well, I wish Tatia the best of luck," Caroline said dryly.

Frankly, regardless of the fact that the triplets were no longer flat chested, she doubted Klaus would ever give the girl the time of day.

"No, I mean she like-likes him."

"Yes, I got that. I'm not an idiot."

Elena gave her a slightly hurt look. "I didn't say you were."

Caroline shrugged, sliding off the bench when the bell rang and walking beside Elena who chattered on and on about nothing in particular. She took her usual seat by Klaus in math class, and got out her notebook before turning to him. Though she was 99% sure that he didn't like Tatia, she felt the need to reassure herself. "Elena just told me that Tatia like-likes you."

He made a hum of agreement. "I've noticed."

"Really?" Caroline asked rather incredulously.

As observant as Klaus was, she hadn't noticed that Tatia was interested. How could she have missed it?

"Yes. She keeps smiling at me and doing that hair-twirling thing that you do around Matt Donovan."

"I don't like Matt Donovan."

"I never said you did," he said, smirking slightly, though she felt like it was...off for some reason.

"Um. Right. Okay. Anyway, you don't like Tatia?"

He shrugged. "She's pretty, I suppose."

"That's not an answer."

He grunted, elbowing her in the side as the teacher started talking. Caroline sighed but quieted immediately, her eyes snapping up to study the whiteboard. Whatever. She didn't care. Klaus didn't like Tatia, and even if he did it was none of her business.

At least, that's what she told herself when she saw them holding hands as they walked down the hallway three days later.

A/N: Thanks for reading. Hope you enjoyed the chapter! Please review and tell me what you thought! :D
As I said at the beginning, this is the prologue, and the next chapter will pick up on their first day of high school :)
Hugs!
-Angie

Copyright 2015, Angelikah