(By the way, you're half mermaid)

You're Percy and Tyson's big sister. You both only recently found out about Tyson. You brought him along to Camp Half-Blood.

You didn't like how Percy and Annabeth treated him.

"We're best friends and bros-"

"We're not bros, we-"

Percy interrupts himself, briefly considering how to continue. "Poseidon is our father, but-"

Tyson looks sad. "Yeah..."

You give Percy a stern look before speaking gently to your baby brother, "Hey, Tyson. Come with me, I want to show you something."