Title: Skin Deep

Author: Night_Lotus

Rating: Mature

Word Count: 939

Chapter: One

Disclaimer: I neither own Chuck nor its marvelous characters, but because of the creative genius of Chris Fedak and Joshua Schwartz, I have the opportunity to play in their sandbox.

Summary: Casey makes Ellie his mission.

Casey rolled his shoulders, grunting as he stretched his stiff, sore muscles, the result of another boring and useless day at the Buy More playing a heavy-appliance jockey. His shoulders weren't the only things that ached. His trigger finger was starting to cramp up; it was getting twitchy, practically begging for a mission. Things had been dry on the spy front for several weeks, and he was hot for some action.

His head was starting to pound from listening to Chuck yammer on as they walked across the Echo Park courtyard. "Well, what did you expect to happen when you left those two imbeciles in charge of the Nerd Herd desk, Bartows—" Casey cut off the verbal dress down and pulled up short, both fascinated and perplexed by what he saw happening in front of Chuck's apartment.

Bartowski's sister was standing with her back to the closed apartment door, facing the two men, unaware of their presence, as she intently looked down the front of her navy blue scrub top.

So many thoughts and more than just a few wildly inappropriate images were whirling around in the blender of Casey's brain by the time Chuck finally got a bead on the situation.

His mouth opening and closing in a non-verbal stutter, Chuck stopped abruptly next to Casey, both hands clinging for life to the strap of his regulation green and yellow Buy More messenger bag.

With his trademark awkward, but determined smile, he let go of the strap with one hand, waving it tentatively in Ellie's direction, trying to get her attention. "Hey, El, off to the hospital?"

The moron was stating the obvious, but it was far better than anything Casey could have come up with, given the situation. At best, he probably would have received a resounding slap if he voiced the slide show taking place in his head right now. Exercising extreme restraint, he clamped his mouth shut, grinding his molars together to prevent himself from offering to help Ellie find what she was looking for.

The smile on the kid's face crumpled, turning into an expression of horrified concern as Ellie continued her intense study, seemingly oblivious to the two flummoxed men standing a few feet away.

Like any battle-tested soldier, Casey knew when it was time to beat a hasty retreat. "Tomorrow morning, eight o'clock, Bartowski," he called over his shoulder, having made it almost to his own apartment door before Chuck turned to look in his direction, the uncomfortable smile still on his face.

"See you tomorrow, Casey," he said with forced cheer, before sucking in his breath and turning his attention back to his sister, silently praying that Casey wouldn't bring this up tomorrow morning before their briefing with Beckman.

Their brief verbal exchange seemed to shake Ellie out of her oblivion, and she looked up to see Chuck walking her way. As she turned on a sunny smile for her brother, she hoped neither he nor Casey had witnessed her visual misgivings on what she had chosen to wear beneath her scrub top.

She had purchased the black, lacy, mostly-see-through Agent Provocateur bra and matching thong on impulse, daring herself to wear them under her work clothes today. It was all part of her plan to reinvent herself, never wanting to hear the phrase "That's boring, babe," uttered in reference to her from any man's mouth, ever again.

"Hi, Chuck, I'd love to stay and catch up, but I'm already running late for my shift." She released her brother from a brief hug and relayed that there was a lasagna and garlic knots in the fridge, before adding "See you in the morning," as she race walked toward the parking lot.

"Uh, bye, El, have a good shift."

Eyebrows nearly meeting his hairline, Chuck watched his sister speed away toward her car, turning back to the apartment door after losing sight of her. As he turned the key in the lock and opened the door, he gave himself a sound mental shake. Alrighty then.

The following morning, Castle…

"So, what's up with your sister, Bartowski?"

And, here it came, the moment he'd been dreading. Thank God Sarah wasn't there, for what little saving grace that was worth.

Chuck swallowed before answering, his Adam's apple bobbing up and down in his throat. "I'm not sure what you mean, Casey, Ellie's fine," he claimed, in a lame attempt to redirect the conversation.

But, all it took was Casey's 'don't bullshit me' look, punctuated by a raised eyebrow, coupled with muscled arms crossed over his chest, to break Chuck.

"Look, Ellie's been trying to deal with her break up with Devon, and it's causing her to act a little differently, is all."

"Hmmph," Casey grunted in response.

Yeah, things with the Intersect's sister were definitely different. Sure, she shared some of the same trademark Bartowski flamboyance that her brother continued to torture Casey with on a daily basis. But, it was more than that, and Casey decided to make it his mission to pinpoint the source of the doctor's recently erratic behavior. He had, after all, been itching for a mission.

Coming up: "Dinner was exquisite," he said, keeping his voice low, as his eyes traveled slowly down her face, latching onto her lips, which parted as if he had coaxed them open with his own.