Author's Note:

Another one-shot... Goody, goody. This time it is not in an alternate universe.

Warning: Percy has a younger sis, Casey. This is set after the defeat of Kronos. Seth does not know about Percy and Casey's secret.

Disclaimer:

Me (roll my eyes): Duh, I don't own the Percy Jackson Series and Twilight. Would I be creative enough to great such awesomeness? Nope. However, I do own the character, Casey...

(someone stage whispers):And published books of said series and saga...

Me (starts sweating): S-so? It's not illegal p-plus I got them as a gift. Honest! (waves arms desperately)

(Cue Evil creepy laugh) Jeez, creepy much?

Sorry for randomness. Anyway, enjoy!

"Yes, it's not raining."

"Yeah, I thought we could go to First Beach, Case. Eat some sandwiches that my mom made," Seth smiled, his cheeks darkened a little against his brown skin. Seth wore a light blue T-shirt and black basketball shorts. He held a picnic basket in left hand.

"Cool. When I called, I thought we would hang out here, but your idea is better. Just let me tell my mom and get ready."

Casey dashed inside after she said that last word, looking like a red and blue blur because of her red T-shirt and dark blue jeans. She let her mom know where she was going and grabbed a dark green parka out of the closet. As Casey closed the front door, she and Seth set out for First Beach.

It has been two months since Paul, Mom, Percy and Casey moved to La Push. After the demigods returned from camp, Paul was offered this amazing opportunity to teach at his old high school at his hometown in Washington. When Percy and Casey first heard about it, for some reason they snorted at the name, La Push; it just sounded funny to Percy and Casey because they were kind of high on blue and green candy. Paul was so excited that he didn't really mind, but they grinned apologetically to mom as she shot the hyper demigods a disapproving look.

Anyway, Paul explained that he was half Quileute and that if they all went he would teach at the school on the Quileute reservation in the town of La Push. He said that he had known of this opportunity for quite some time and talked it over with their mom. The only thing left was how the teens felt about it. Despite feeling that they were abandoning their city and Camp Half-Blood, Percy and Casey decided to go along with it since they need to look out for recruits as well as watch out for monsters.

So far, their time in La Push had been okay. True, the siblings did get in some fights with some knuckle-head mortals who wanted to pick on the newbies but they took care of that. The only thing that surprises them was that there were no monsters coming to attack them. For the first few weeks, they felt relieved that they have survived with no monster attacks; however, Percy and Casey grew uneasy as more weeks passed by with no sign of monsters. Either the monsters were planning something big or they decided to leave the teens alone. Casey seriously hope it was the latter.

With nothing much to do except scout the area and keep a look out for monsters, the teens made some friends and hang around First Beach. They were thankful that they were near the beach as it is their father's territory.

After Seth and Casey had their picnic that his mom made for them (gods, that chicken sandwich was awesome!), they dropped off the picnic basket at his house. They decided (well, Casey pleaded and Seth reluctantly agreed) that they would take a walk in the forest. They took a trail that mostly lead westward.

The forest was a bursting green with almost every surface covered in green moss or grass. The fallen trees, rocks, and tree trucks were covered in green. The ground was covered in long dark grass and bushes, some with flowers while others without. They kept walking and following the trail; their weather-proof boots crunching twigs and damp leaves. They stopped after two miles of walking and rested on a log that had recently fallen. It was a little damp so she placed her jacket on log and sat. She moved to give more room for Seth to sit.

They sat talking, playing twenty questions. Casey almost fell over laughing; the story in which he purposely painted his older sister's favorite T-shirt was just hilarious. He was nine and mad at his sister, Leah, for not letting him come with her and her friends to the city. As revenge, he took his sister's T-shirt that she won at a concert where her favorite band was playing. When Leah came back, she chased him all over the house for painting rainbows and hearts on the T-shirt. His mom fell for the cute puppy-dog eyes and let him of the hook if he apologized to his sister.

Casey described a prank she pulled on her older brother, Percy. She had drawn on his face a moustache, a pointed beard, and eye shadow with a Sharpie marker. Percy had awaken after she had showered and headed to kitchen for breakfast. Then, he had come into the living room (green eyes flashing angrily and mischievously) set on tickling Casey to death to get her to say sorry while their parents laughed.

By the end of the story, Seth was holding his stomach and had tears running down his cheeks as he laughed. The booming laughter echoed through the forest. He has such a nice laugh…sweet and boyish with—err…moving on.

Casey looked away to hide her blush. She looked up to see that it was getting cloudy meaning the possibility of rain.

Casey looked back to see that Seth stopped laughing. His warm brown eyes twinkled as he grinned. A chilling breeze blew by, but she didn't notice the cold; either because she was Poseidon's daughter (immune to cold especially in rainy places) or because she was distracted by the wind tossing a few strands of his dark brown—almost black—hair.

Again… Curse her hormones.

At least, she got over being uncomfortable that he doesn't wear a shirt most of the time which is weird because shouldn't he get cold… Casey seriously couldn't help it as her thoughts turned to his chest. Seth was developed, but not like his friends who look like they were on steroids. He was more lean and gangly but still had a nice six-pack. Yum.

Uh…Scratch that.

Casey shook her head to clear her thoughts. She stood up, brushed off dirt on her dark jeans, and asked, "Hey shouldn't we go back? We have been here long enough; it's already mid-afternoon."

He didn't say anything; Seth had this look of thoughtfulness as if coming to a decision. He looked up at her and Casey had this sudden urge to blush; he had fixed her with an intense gaze, a strong emotion dancing in those bright brown eyes.

He stood up and moved in front of her, towering over her 5'7" height with his 6 feet and 4 inches long body.

"Seth, is everything okay?" Casey asked, concerned about his odd behavior.

He rubbed the back of his neck then ran the same hand through his hair; he does this every time he gets nervous. Making eye-contact with Casey, Seth took a deep breath.

"Casey, I have something to tell you. I'm a—"

At that moment, her brother appeared, Riptide drawn and face set in warrior mode. Casey only had time to pull her weapon, a dagger hidden as a belt clip, step in front of Seth with a sheepish look, and block her brother's attack.

Whoops. Maybe I shouldn't have told Seth that story, Casey thought.

Parrying away Percy's weapon with her dagger, Casey spun and kicked Percy. The force sent Percy flying and crashing into a tree.

She looked back and wished she hadn't; Seth was looking at her and gaping with disbelief. Casey cursed in Ancient Greek. She did not want him to find out about her secret this way.

Oh, well, Casey thought as she turned to face her brother with gritted teeth and eyebrows pulled together. He's gonna find out now. Thanks, bro, nice one.

"Get back Seth!" Casey hissed behind her as her blade met Percy's Riptide in the air.

Case—did you just—that did not—why is your brother—whoa!"

While Seth was blundering, Percy managed it get through Casey's defense and took a swipe at Seth. Fortunately for Seth, he dodged out of the way. Unfortunately for Percy, the action made Casey really angry.

She jerked Percy by the collar of his navy jacket throwing him to the ground. Casey clicked a button on the hilt of her dagger; it grew into a 2 and half feet long sword of celestial bronze.

She took a swipe at his head as he got to his knee. Percy threw himself backward and rolled back into fighting stance.

Casey didn't think only attacked. Her mind went on auto-pilot and was hyper-aware. She smiled as her ADHD kicked in, saving her from being skewered badly as Percy tried to stab her. Out of the corner of her eye, Casey saw Seth edging towards their fight his expression filled with worry, caution, anger, and indecision. His whole body was shaking whether in anger or worry; she could not tell.

Casey was so focused on Seth that it gave enough time for her brother to knock her back with a backhand to her collarbone. She fell backward hitting her head on a root leaving her disoriented. Her sword flew a few feet away from her, behind a rock.

Percy turned to Seth.

"You," Percy growled out menacingly as he brought the sword, gleaming golden bronze as it caught the little light, in front of him pointing at Seth. "You monster! You think you can get my sister alone and kill her!"

Percy took a step towards Seth and swung the sword in an upward arc.

Seth jumped back; the 3 feet long sword passing through the air that had occupied Seth's torso. Seth had his hands up in a gesture of surrender. "Man, take it easy. What are you talking about?"

Percy jumped up with both of his hands holding the sword intending to bring down on Seth's head.

"I am talking about you being a werewolf, you mutt!" Percy shouted, his voice scaring away birds in the trees.

Seth was stunned; he couldn't move out of the way or defend himself. All that ran through his head was how did he find out?

Seth felt himself being knock aside. He sat up in his dirt smudged clothes and found Casey with her hands, though shaking under pressure, holding her sword in lock with Percy's where Seth had been moments ago.

Casey looked fine except for a bruise on her temple from when she smashed onto the ground and a graze when Percy had gotten a lucky hit. Her shoulder length dark brown hair was filled with small twigs and leaves. Her clothes looked rumpled and dirtied; her jeans had green and brown streaks and her shirt was ripped and on one side had a big brown smudge. Her black sneakers were the only thing that looked fine.

Percy was sporting a bruise on his left arm from when he landed on the ground and a long cut on his forearm. His clothes, which consists of a navy windbreaker, a gray Hawaiian shirt, and jeans plus sneakers.

Though Seth was worried that she was hurt (felt the rising anger from the pit of his stomach in response to that), he could see that Casey didn't care about that. She had a very funny—no scary—expression on her face: her face was smooth but her darken green eyes blazed with anger and determination. Come to think of it, Percy also had a fierce cold look in his own sea green eyes with eyebrows furrowed and lips in a tight line.

"Percy, Seth is NOT dangerous." Casey hissed, letting Percy's slid down her sword unexpectedly. Percy stumbled but blocked Casey's next strike.

The two began exchange strikes. Casey kept pushing Percy back away from Seth. Percy tried to get through her defense, jumping in and out as he looked for a weak point.

They were screaming at each other sometimes in a different language and others in English.

"—gods, you idiot—"

"—that guy is a monster—"

"—the hell he is, val—"

"—you don't know—"

"—oh so I don't!—"

"—you have to understand—"

"—no I don't! You have to—"

"—will you listen—"

"—why should I—"

"—I'm your brother. I'm supposed to—"

"—yeah, you're supposed to support me. INSTEAD OF TRYING TO KILL HIM!"

The sound of clashing metals and human grunts filled the air. Casey, her eyes flashing dangerously, thrust her sword upward catching a little of Percy's shirt and tearing it. Percy, hissing through his teeth, parried it away and leaned forward to swipe at her torso. Casey twisted away, dropped down, and, while using the momentum of her spin, kicked her leg out. Out of instinct, Percy jumped up to avoid her leg while stabbing his sword in the direction of her neck missing by an inch as Casey dodged narrowly.

The fight progressed and the two siblings each got a couple of good cuts on the other. It turned deadly as each tried to gain the upper hand.

Seth tried the only thing that he knows that may stop them as the fighting got intense between the siblings: he got re-enforcement. He knew he could not go in between them because either he will get hurt or one of them will get hurt. As he took off running, he shoved away the thought of how Percy found out about him a werewolf; he will worry about that later.

He skidded to a stop almost tripping over a dead tree. Stepping into a bush, he pulled off his clothes and, like Jacob, rolled them up to tie them to his leg. Once he was done, he felt the heat go up his spine and spread through his body.

Dropping on to four legs, Seth shook out his sand-colored fur and ran out towards where he knew Jacob was. He could everyone's thoughts now.

Hey, Seth how was the date? Embry sent, teasingly.

Did ya kiss her? Quil made kissing noises.

Ugh, I hope I don't have a repeat of your dream. Leah mentally shuddered.

Then there was a chorus of mental chuckles and catcalls.

GUYS! Shut up, Seth thought. They're in trouble.

What? Collin asked, stunned by the outburst.

Seth answered with the memories that had happened a few minutes ago: the words of Percy, You being a werewolf, you mutt; the angry cool expression on Casey's face; two bronze swords clashing in the air; the injuries the two siblings inflicted on each other.

The silence that followed spoke more words than anything else.

Jacob broke it, going into Alpha mode. Seth, stay near them but stay hidden. We don't want you hurt. Leah—Embry—Quil, you guys and I will find Seth so we can pry them apart. Collin and Brady: tell Sam what happened and ask him to come by.

Everyone muttered their agreement though Collin and Brady were sadden that they won't miss the fun. They wondered if the siblings would be willing to teach them a couple of moves once they calmed down.

Can't believe my brother scored a kick-ass chick…wow. Leah thought, stunned but pleased.

Damn, did you see that move she did on Percy? The one where she spins, her leg out in a hook, and ready to hit with her heel? So cool! Quil thought, excited to ask for fighting tips.

Embry his shook big wolf head as he ran with a sleek gray wolf smaller than everyone on the pack and a chocolate colored wolf. He thought. Guys, have you considered that maybe it's not the best time to talk about that?

Why not? Collin questioned as Brady commented, it is hard not to talk about it.

While they were chatting (Seth ignoring them), Seth ran back to where he left the Jackson siblings. His paws digging into the soft ground and the wind ruffling his fur. He slowed as heard the sounds of shouting and clashing metal.

Seth carefully sneaked in on his belly, making sure not make any unnecessary noise. He flattened his massive gangly body on the ground and peered between a bush and the trunk of a tree.

Seth watched as Casey let out a pained groan as her back hit a big spruce tree.

She dodged to the side as Percy slashed a thick cut into the tree's flesh where she had been. On one knee, Casey swung her sword in an upward arc from her side simultaneously standing up. Percy swiped the blow away, locked his sword under hers, and with a flick of his wrist knocked her sword out of her hand.

Casey quickly kicked at her brother's knee. As Percy stumbled, Casey brought her leg up to land a high kick…

Embry wrapped his hands around Casey, his arm on top of hers in a tight embrace. Quil had done the same thing on Percy while knocking away his sword.

With many curses directed as the two shape shifters, Casey and Percy grudgingly promised to behave lest they be released.

Seth let out a sigh of relief. He promptly got up, shook out his fur, and morphed back to his human form after hiding in the bush.

Putting on his pants and shirt, he stepped out.

Several things happened at once: Percy brought out a pen which turned into a sword, Casey had her dagger in hand (which she had secretly took from the ground) and moved in front of Seth in defense position, Embry and Quil clamped a hand on each of Percy's shoulders.

Casey snarled angrily at Percy. Percy shook the hold on his shoulders and turned his back on Casey to face Embry and Quil.

Percy, holding his sword loosely, asked, "What are you?"

"We could ask you the same." A different voice washed over area.

Everyone looked up at the interruption; Percy swerved to face Jacob, who had spoken, Sam, Leah, Brady, and Collin. All were dressed in shorts along with Seth, Embry, and Quil (Casey noticed that all the boys were shirtless except for Leah and Seth) who had moved to stand next to the five in front of the siblings.

Percy snarled and raised his sword threateningly. His green eyes flashing angrily as Percy said, "Who in Hades do you think you are? Casey, you should know better than to trust monsters—"

"I ALREADY KNEW HE WAS A WEREWOLF, YOU VLACAS!"

Casey breathed heavily as everyone stared at her in various degrees of shock. Seth was the most apparent: his eyes were so wide that any further Casey was sure he would end up mistaken for a fly's cousin and his mouth was open, jaw hanging loosely.

Seth managed to find his voice, though shaky and in awe. "Y-you k-knew. Already? H-how?"

"Wolf tracks," Casey replied, voice hoarse. "One time, you came out of the forest and went with Jacob to do something. I figured the place you came out from was safe so I went for a walk and the footprints slowly turned to wolf paw prints the further I went into the forest.

"It wasn't hard to figure it out from then on," Casey continued, "I heard from Paul the myths of the Quileute and how you changed into wolves. I spent time with you trying to figure out whether you would kill me or not. But even when we were alone, especially those times that I did not know what you are, you didn't even try."

Casey smiled softly at Seth, her green eyes bright. A light drizzle began to fall.

Casey took a deep breath and turned to her brother, Percy, and said, "Now you know why I trust him?"

Percy shook his slightly wet black hair. "Yeah I get it. Wished you told me sooner."

Casey rolled her eyes.

Jacob said thoughtfully, "Well, that makes sense."

Leah snorted, "Trust little brother to expose us that way."

Brady and Collin grinned as Embry said, cheekily, "Wow, Seth, aren't you going to say anything?"

Seth cleared his throat and said, "Thanks for not making me explain myself."

Casey smiled brilliantly.

"But why are you carrying swords and what's with the weird language?"

Casey's smile froze, and she looked to Percy for help.

Percy backed away with his hands up, and green eyes glinting mischievously.

"You're on your own, sis."

Author's Note:

Damn! I'm such a tease. XD

Whew! Second one-shot done. Now that you read... please shower me with compliments ;). Review, please, so I know where to improve.

Thanks for reading and a special thanks to BloodyInsanity5713, LadyItachiUchiha, and Charm0900 who were among the first to review and favorite my first one-shot, My Weasel. 'Til next time.

C-Shady