A/N: Hi everyone! This is my first foray into the world of A/U PJO - the idea came to me this morning & I decided to go for it. Reviews & constructive criticism, if you have any, are greatly appreciated - I want this to be the best I can make it. Rick Riordan owns everything PJO/HoO-related, I just own the plot. Enjoy! :)

"Annie, Annie, Annie, it's the first day of school!" The boy jumped up and down as he greeted his friend.

"Percy! Don't call me Annie!" The little girl stuck her tongue out, clearly disgusted with the nickname.

"Sorry…" He briefly looked down at his new shoes, a sheepish expression on his face. "But it's the first day of school!"

"I know! It's finally here, yay!"

Sally smiled as she watched her son's interactions with his best friend. They'd been counting down to their first day of kindergarten all summer, crossing off the days on the giant number chart they'd made themselves, and the big day was finally here. Percy's superheroes backpack was almost as big as he was, and his matching lunchbox made a soft "clunk" as he set it down on the sidewalk. Annabeth's purple lunchbox, covered in horses, rested right next to his. The two friends hadn't stopped grinning since they reached the bus stop, and both bounced on their toes in anticipation as they eagerly watched for the bus.

Moments later, the bus came into view, its bright yellow paint glinting in the morning sun. Suddenly, Percy didn't look so eager.

"Annie-beth," he whispered, reaching out to grab his friend's hand, "I'm scared." Despite the whisper, Sally heard her son's words.

"Don't be scared," the girl reassured him. "We're best friends. We can do this." She smiled and squeezed his hand, and he smiled back.

"Yeah, we can," he finally said. "Love you."

"Love you too."

Sally smiled as she remembered the first time the two friends had exchanged those words – it had been the day they first met, nearly two years ago now, but she remembered it as if it were yesterday:

"Percy, be careful, honey!" Sally said as her son nearly toppled over in his haste to try out his new tricycle.

"Mommy," he whined. "Lemme try!"He managed to get on the first time, and he laughed as she gave him a push. The tricycle went about three feet before he veered to the left and got stuck in the grass, but the pure joy on his face told her he didn't really care. She couldn't help but smile as she helped him straighten out again.

A squeaking noise caused her to look up, and she saw a little girl, probably close to Percy's age, riding a tricycle in their direction. The child pedaled confidently and kept her wheels straight – she obviously either had had her bike longer, had had more practice, or both. When she saw Percy and Sally, she stopped.

"Annabeth, sweetie, wait for Daddy!" A tall, thin man with messy hair and glasses ran up to the little girl, holding the bike still with his foot and bending down to her level. "You know you're not supposed to go off without me," he scolded, but his tone was gentle. Sally could tell he loved her very much.

"Sorry if she was bothering you," the man said to Sally.

"No, not at all!" Sally replied.

"Ok, good. She just got the bike for her birthday and is still really excited." He stood up and offered his hand. "Frederick Chase, and this is my daughter, Annabeth." His handshake was firm, his eyes kind.

"Sally Jackson, and this is Percy. We just moved in. Today is Percy's third birthday."

"Oh, well happy birthday, Percy! Annabeth just turned three last month."

During their parents' exchange, the two children cautiously got off their bikes and studied each other. Percy thought the girl's blonde curls looked like a princess's. He didn't really like princesses – they were for girls – but he liked this girl's hair. Her eyes were dark gray and reminded him of a storm cloud, which was a little scary, but she smiled, and he decided that anybody who smiled couldn't be that scary.

"Hi," he said shyly. "You're pretty."

Annabeth giggled. The boy's dark hair was almost black – Annabeth didn't like black, but she didn't mind it on him – and his eyes were a beautiful shade of green. Not like grass, or trees, or even Daddy's car – Annabeth couldn't decide what the shade was – but she liked it a lot.

"Thank you," she said, remembering her manners. "Want to be my friend?" He smiled at her.

"Yes!" Then, because he hadn't really been listening to his mom's conversation, he asked, "What's your name?"

"Annabeth," she said.

"Annie?" he asked.

"No!" she made a face. "Don't call me Annie!" It came out a little louder and more forceful than she intended, and her father heard her.

"Annabeth," he cautioned, "Be nice."

"Sorry," she said, her voice small. "My name is Annabeth. What's yours?"

"Percy," her new friend replied.

"Percy…I like it."

"Thanks! I think it's kind of weird, but my mommy says it's a special name, because I'm special." His face lit up. "Want to see my bike? It's my birthday!"

"Ok!"

The two children compared bikes as their parents made idle chit-chat.

"Looks like somebody's made a new friend today," Frederick said with a chuckle.

"I think so," Sally agreed. "I'm glad, I was worried when we moved in that there wouldn't be any kids around here."

"Oh, there are plenty," Frederick said. "Most of them are a bit older, though. I think Annabeth is pretty happy to have somebody to play with right about now."

"Percy, too." She paused. "His father died a few months ago. He's too young to understand why, but he knows Daddy isn't coming home anymore. I think…I think having a friend will be good for him." She had no idea why she was telling this to a complete stranger, but she felt if that stranger's daughter was to play with her son, he had a right to know.

"I'm…sorry for your loss." Frederick knew it was a lame response, but he couldn't think of anything better. "If you need anything, please let us know. And Percy is welcome to play with Annabeth whenever he wants."

"Thank you. That means a lot." She looked at the children, who were sitting in the grass a few feet away, their tricycles abandoned on the sidewalk.

"Annabeth, honey, it's time to go inside for supper," Frederick said.

"I don't wanna." She pouted. "I wanna play with Percy."

"Percy lives right next door, sweetie. You can play together whenever you want."

"Really?" Her face lit up at the idea.

"I can play with Annie-beth all the time?" Percy asked him, his eyes wide.

"Sure can, buddy." Frederick smiled at the little boy. "We have to go home now, but you can play tomorrow if you want to."

"Mommy, can I?" His smile was infectious.

"You sure can, sweetie." Sally smiled at her son, glad to see him so happy.

"Yay!" Percy clutched his mother's hand and waved at his new friend. "Bye Annie-beth, I love you!" The little girl stared at him.

"Oh, um…sorry," Sally said, a little flustered. "He's just going through a phase where he says that a lot…"

"I love you too, Percy." The little girl's response took Sally by surprise, but she smiled again as Annabeth gave Percy a hug. Clearly, little kids had very few inhibitions about stuff like that. Sally could already tell Annabeth was a good friend – if the little girl made Percy happy, that was good enough for her.

That "I love you" became like their personal mantra – sometimes one would initiate it, sometimes the other, but no matter what, the two friends always made the exchange right before they parted.

The two children boarded the waiting bus and found a seat near the front. Sally couldn't see from her perspective, but she somehow knew they still hadn't let go of each other's hands. She waved, and Percy waved back, mouthing, "I love you" as the bus pulled away.

"Think they'll be alright?" came a voice from behind her. Sally turned to greet her neighbor.

"Of course they will, Frederick," she said. "They've got each other – they'll be fine." He knew she meant it, and so did she. As long as best friends were in it together, they could get through anything.