A/N: Me: OK Welcome To My First Story Ever. It's An AU Where Percy Is Bianca's Twin And There Is A Son Of Poseidon Named Mark. OK On With The Stor-

Percy: Wait, You're Forgetting The Disclaimer!

Bianca: Yeah!

Me: Ok.

Disclaimer: I'm 14, Do You Think I Could've Written Such Awesome Stories?

Chapter 1: Westover Hall

Mark's POV:

The Friday before winter break, mom drove Thalia, Annabeth, and me to a school called Westover Hall. It turns out Grover has found 3 powerful half-bloods here. It was an 8 hour drive to Westover Hall.

As we pulled up, Thalia wiped some fog off her window. "Oh yeah. Fun." She said sarcastically.

Westover Hall looked like an evil knight's castle. It was all black stone, with towers and slit windows and a big set of wooden double doors. It stood on a snowy cliff overlooking this big frosty forest on one side and the gray churning ocean on the other.

"Are you sure you don't want me to wait?" my mother asked.

"No, thanks, Mom," I said. "I don't know how long it will take. We'll be okay."

"But how will you get back? I'm worried, Mark."

I hoped I wasn't blushing. It was bad enough I had to depend on my mom to drive me to my battles.

"It's okay, Ms. Jackson." Annabeth smiled reassuringly. Her blond hair was tucked into a ski cap and her gray eyes were the same color as the ocean. "We'll keep him out of trouble."

My mom seemed to relax a little. She thinks Annabeth is the most levelheaded demigod ever to hit eighth grade. She's sure Annabeth often keeps me from getting killed. She's right, but that doesn't mean I have to like it.

"All right. Stay safe." my mom said.

"We will Ms. Jackson." Annabeth said. We then exited the car. The cold air cut through my coat like ice daggers.

"Your mom is so cool, Mark." Thalia said once the car was out of sight.

"She's OK." I admitted. "We should get inside."

"I wonder what made him sound the distress call if he's already found them." Thalia remarked looking at the school.

"Probably a monster." Annabeth speculated.

(I'm skipping the meeting with Dr. Thorn and Mrs. Gottschalk. It's a stupid thing to me.)

"So Grover why did you sound the distress call if you've already found the half-bloods?" Annabeth questioned.

"Monster." He simply replied.

"Who?"

"Dr. Thorn."

"Who are the half-bloods?" I questioned.

"Over on the bleachers." He pointed to three kids who were sitting there. Two boys and a girl. They all had olive skin and black hair. The girl, who looked the same age as one of the boys (About 14), wore a green floppy hat, black jeans, black shirt, and a jacket. The youngest boy was hunched over a deck of cards with the oldest boy looking over his shoulder. So they looked like siblings.

"OK, let's act natural." Thalia suggested.

"Good idea." I replied. Annabeth grabbed my hand while Thalia grabbed Grover's.