Waiting by the canoe lake for Evelyn, Piper fidgeted her hands nervously behind her back. Why am I nervous? she thought. It's not like we're going on a date or anything. Just a friendly run. Piper spotted Evelyn heading towards her in their teal running shorts.

"Ready to go?" she asked.

"Let's go!" Evelyn replied enthusiastically.

"Just follow me, I have a path that I always run." Piper started jogging towards the firework beach and Evelyn followed. They ran side by side in silence until Piper spoke up.

"So, earlier, when Percy told me about you, he called you his sister. Now you're his sibling. How does that work?"

"I'm genderfluid," Evelyn explained. "That means different things for different people, but for me, some days I'm female and some days I'm non-binary."

"Neat. Annabeth's cousin's partner is gender fluid, but they go between male and female."

"That's the most commonly known variant of being gender fluid, but people can go between any genders, and there can be more than two that they go between."

"Awesome," Piper responded enthusiastically. Evelyn offered her an earbud. "Are we allowed to listen to music?" Piper questioned.

"Relax, it's a tape player. I recorded some of my favorite songs on it."

Piper put in the earbud. Evelyn hit start, and a song Piper didn't recognize began playing. "What's this song?" she asked.

"Music Box by Malinda Kathleen Reese. One of my personal favorites."

"I've listened to some of her songs! Her voice is amazing."

"I know, but shhh, listen." Evelyn put their finger to their lips.

And Piper listened.