Percy Jackson was fed up with his dad. He'd only been back from Hera's quest for two weeks and Poseidon had another quest for him. Annabeth squeezed his hand reassuringly. "Why do you want me to find this person? Who is it?"

"You need to take Jason with you."

"Dad, what aren't you telling me?"

"Vanessa is a demigod. She's your sister but she's also a descendant of Venus and extremely powerful. Be careful, Percy."

"Wait, Venus? Is she in Camp Jupiter? I have a sister?" Percy was confused.

Poseidon sighed. "She is my daughter through my Roman form. Now go. Take whomever you want, but Jason Grace has to go." The Iris-message disappeared, cutting off his last question.

"Call the gang, Annabeth. I'm going to get permission."

She nodded, but her eyes were worried. Percy ran over to Camp Half Blood's director to explain what was going on and she rounded up the other demigods. Soon, Jason, Piper, Leo, Hazel, and Frank waited to see who could go with Percy. Dionysus or Mr. D, as they called him, was gleeful at the thought of getting rid of Percy for a week or two. "I can allow four to go, and as you said Poseidon said, Jason and you make two. Who else?"

"Leo needs to go so he can sail the Argo II and Annabeth will come too, because she's smart." Percy said matter-of-factly.

"Oh good, you may leave at as soon as possible. Have fun kiddies." Mr. D left, laughing hysterically.

"Why do I have to go?" Jason asked.

"I don't know. Dad said I would need you, though. Leo, as soon as you get the ship ready and we pack, we can leave."

He felt bad about not taking the others, but he chose the best tactically. If Jason didn't have to go, he would've chosen Frank, but disobeying a god's direct orders was bad. He packed quickly and closed the door to his cabin. In a matter of minutes, the ship was sailing through the skies and Percy called a meeting. "The quest is to find my sister. The thing is, Dad said she's a Roman demigod and her first name is Vanessa. He didn't tell me anything else."

"The obvious choice would be to go to Camp Jupiter." Annabeth said.

"I would've remembered another child of Neptune, though."

Jason, whose face went pale at the name, spoke up. "She left before Hera switched us, Percy. I can't really remember what happened, but it involved Octavian. Reyna might know something, though. She and Vanessa were good friends."

"What's she like?"

Jason scowled. "She and I didn't get along."

"Get ahold of her and let her know we'll be there tomorrow." Percy directed this at Annabeth, who, out of the four, was on the best terms with Reyna.

She pulled out Daedalus' laptop and proceeded to email the lead praetor of the Roman camp. Within seconds, she had a reply. "Reyna said only Percy and I would be allowed."

Jason sighed. "I'm guessing she's still mad at me and Leo, then."

Leo shrugged. "I'd rather be on the ship anyway."

The next day, the ship floated over the beautiful valley ringed by the Oakland Hills. Leo rolled the rope ladder over the side and they descended into New Rome. A tall girl with dark hair and black eyes came to meet them. She gave Annabeth a hug and shook hands with Percy. "What's going on now, Jackson?"

"I'm looking for my sister. Jason said you and Vanessa were friends."

She sighed. "We are. She's living in San Francisco with her boyfriend, but before you go after her, there's some things I should tell you."

A tall, stringy haired blonde ran over. "Not him again!" He groaned.

"Octavian, shut up. He's looking for Vanessa."

Octavian's face changed rapidly from annoyance to hatred. "Why doesn't he just ask Jason? He'd know where she's at."

"Go away. They won't be here long."

He stalked off, muttering under his breath. "Umm, Reyna, what's going on?" Percy asked.

"You have to ask Jason about what happened between them, but Octavian hates Vanessa because she embarrassed him tremendously in front of everyone during practice. She left due to what happened with Jason and ran off with a Greek she met on a quest."

"What's his name?"

"She didn't say. She was upset and I still don't know the whole reason she left. It's complicated, Percy. I wish I could tell you more but that's all I know."

"Thanks, Reyna. We appreciate it." Annabeth watched Octavian out of the corner of her eye. "I'll let you know when we find her."

"Good. Be careful and good luck."

They climbed the ladder back to the Argo, where Jason and Leo waited. "Where's she at?" Leo asked, already heading to the controls.

"Get the ship on water, Leo. We'll sail to San Francisco that way."

Leo ran off and Percy turned toward Jason. "Why doesn't Octavian like Vanessa?"

"Octavian doesn't like her because we made her a praetor instead of him and she pulled a massive prank on him during practice. She filled his helmet with pink Kool-Aid and when he put it on, it turned his hair hot pink."

Percy snorted. "That's why he hates her?"

"She also turned him down when he asked her out. My swordplay's a bit rusty, so I'm going to practice."

"Dude, mine too. I'm coming with you."

Percy walked off with Jason, both swinging their swords around. Annabeth went to join Leo at the helm of the ship as they touched down in the Pacific. "I wonder what she's like." Leo mused, turning around to face her. "Where's Percy and Jason?"

"They are working on their swordplay." She leaned against the rails. "She has a Greek boyfriend, so she doesn't hate us, but Poseidon warned us to be careful."

"That's always a good sign when the gods tell us to watch our step. Is she older than Percy?"

"I think…what was that?" A loud crash sounded from below deck and Annabeth raced down to the practice room to find the boys laughing hysterically at something. "What happened?" It looked like they destroyed one of the dummies.

"If we work together, wooden dummies are no match for us." Percy choked out, still laughing. "We still have a little while until we hit California."

"Dude, how do you know that?" Jason asked, getting a breath.

"It's a son of Poseidon thing." Percy joked, jabbing another dummy.

A few minutes later, Percy stood behind Leo, telling him where to go. "Turn portside."

Annabeth walked up to his side, taking his hand. "How are you figuring out where she lives?"

"Dad." He said simply as the beach came into view, along with a lone figure watching the ship approach. Percy lifted the water, allowing the ship to sail right in front of a cozy cottage. He finally got a good look at the figure in the water- a slender, petite girl with a long deep brown braid hanging to one side of her face. She waded through the water to where the trireme docked. "She's a beauty! Who's the captain?" She cupped her hands over her mouth so they would hear her.

"Leo Valdez! May we come down?" Percy yelled back.

"Sure, why not? I could use the company."

They climbed down the ladder- Percy first, followed by Annabeth, Leo, and Jason. She stood with her hand on the hilt of an Imperial gold sword in the sand, tip first. Her eyes narrowed as they drew closer and Percy realized she was glaring at Jason. "Are you Vanessa?" Percy asked nervously. The look in her ocean blue eyes was one of deepest loathing.

"Vanessa King, daughter of Neptune. You are?" Her gaze didn't stray from Jason.

"Percy Jackson, son of Poseidon. Dad sent me to find you."

"And you just happened to bring Sparky with you?" She snapped one hand on her hip.

"Sparky?" Leo sniggered.

She turned her eyes on Leo, giving him a once-over. "You must be Leo. Where'd you get the ship?"

"I built it, except for Festus the dragon. Want a tour?"

"Definitely but not right now." She glanced back toward the cottage. "Let's go inside."

Percy let Leo follow her and he took the rear, behind Jason. She plopped down in an oversized armchair. "Sorry about not introducing everyone. This is Annabeth, daughter of Athena, and Leo's the son of Hephaestus. You already know Jason."

"Sparky." She corrected. "No wonder you smell like smoke, Leo. No offense."

He shrugged. "It's cool."

"So Dad sent you after me, huh? Did you have a particular reason for bringing him?"

"Dad said Jason had to go but he left before I could ask why."

"Typical." Jason was looking at a brilliantly silver long sword hanging on the wall behind him. "Sit down, Sparky." She ordered.

Percy felt the effects of her charmspeak wash over him and Jason immediately sat down. "You charmspeak?"