Title: Crossing the Line

Author: Night_Lotus

Rating: NC-17

Word Count: 2,860

Chapter: 3, Part I

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: Ellie accidently intercepts an email meant for her brother, Chuck, and is left with the Intersect computer embedded in her brain. She and her NSA handler, Major John Casey, are tasked with a delicate operation by General Beckman. Casey sleeps over.

Author's Note: AU, but takes place mostly within the Season 2 timeframe of "Chuck." Any errors and/or omissions are mine and mine alone. Since this chapter is a bit long, it will be split into two parts. Thanks for joining me on this journey.

Present Day, Castle

"Hmmmph," Casey grunted as he took inventory of the grenades and other ammunition lining the shelves. "Been going through these like water lately," he commented with a frown as he made several check marks on the official NSA Munitions Order Form attached to his clipboard.

The sudden vibration of the cell phone resting in his pocket provided a welcome diversion. He pulled it out, flipped it open and read the text message on the screen. Dinner 6:00. Don't B late. Wear something sexy. ;-) The corner of his mouth curled up in a smirk. "Heh."

The crease between Sarah's eyebrows deepened as she focused on writing her monthly report summarizing the missions Team Bartowski completed, including the number of captures, casualties and cleaner teams required for each assignment. "New mission orders, Casey?" She questioned as she turned around, looking in his direction.

"Something like that. Beckman gave me and the Intersect a new assignment, and we're working on firming up our covers tonight."

A smug smile played at Sarah's lips as she shot Casey a knowing look.

With a curt nod of his head, he gestured toward Sarah's phone, which was lying on the table a few inches from her hand. "Hey, Walker, is that your cell phone ringing? It must be the kettle calling back."

"That's not fair, Casey!" she volleyed back as she watched him sling the strap of his black backpack over his right shoulder and climb the stairs.

"What would either of us know about fair?" he tossed over his shoulder with a wink.

"Touché, Casey. I just hope neither one of you ends up getting hurt," she whispered, concern visible in her blue eyes, as she watched his black combat boots disappear from view at the top of the stairs.

The changes in the interactions between the Asset and her handler were subtle and had developed slowly over the duration of the assignment. No one but Sarah Walker really realized or paid any mind to the shift in dynamic. To the outside world, they were simply John and Ellie, an unexpected, yet seemingly storybook illustration of opposites attracting. But, to Walker's trained eye, they were much more.

Castle, two weeks prior…

Upon their return to Castle after a successful mission, adrenaline was running high. No one had gotten shot, stabbed or blown up. Chalk one up for Team Bartowski. Even Casey was in a good mood, reflecting on how they successfully liberated the schematics for a dirty bomb from the personal safe of a suspected terrorist, who was now being "rehabilitated" in a secure underground government facility.

"We got in, we got out, we got what we came for," Casey summarized for General Beckman, debriefing her on the mission as the three of them sat at the conference table.

"Good work Major, Agent Walker, Doctor Bartowski," Beckman stoically praised the team before abruptly killing the comm. link with a quick jab of her index finger.

Casey caught the way the corners of Ellie's mouth twitched as she tried and failed to hide her smile. Her smile grew even wider when Casey turned to her and asked "Wanna share what's so funny, Doc?"

"Really, John," she laughed, turning in her chair to face him. "We got in, we got out, and we got what we came for? Isn't that your normal M.O., or do you just save that for the bedroom?" she teased.

Sarah failed to suppress a snort of laughter, which earned a narrow-eyed glare from Casey before he rose slowly and purposely from his chair.

A smile still lighting her face, Ellie watched as Casey advanced upon her. She never tired of watching him move. Given his substantial size, he traveled with a surprising amount of fluidity and grace.

Still dressed in his black mission gear, he reminded her of a panther. The powerful muscles of his thighs strained against the fabric of the cargos as he stalked closer, swallowing the inconsequential gap between where he had been sitting and where she remained seated. The ribbed combat jersey clung to his arms and torso like a second skin. Her breath involuntarily caught in her throat as she witnessed his biceps flex and his pectoral muscles shift as he loomed over her, resting his hands on the conference table on either side of her, creating a private enclosure as he leaned down and whispered in her ear.

Lord, the man radiated heat, and she was instantly cocooned in warmth. She shivered involuntarily as her body reacted to the change in temperature and his nearness. Her eyes closed and her nostrils flared as they filled with the scent of tobacco, sweat and man. Goosebumps blossomed along the column of her neck as his lips brushed against the inner shell of her ear and the hushed secret vibrated against her eardrum.

He withdrew, smirking as he watched her cheeks redden. She licked her lips, her eyes still wide, as she stood shakily.

She smiled nervously at Sarah and completely avoided eye contact with Casey, as she headed for the exit. "I'd better go. I have some errands to run and an early shift at the hospital tomorrow."

Maintaining a neutral expression, Sarah rose from her seat at the conference table and casually stretched. "Okay, Ellie, get some rest, and we'll touch base tomorrow," she offered the suddenly unnerved doctor a small, reassuring smile as Ellie began ascending the stairs that led out of Castle.

As soon as she was certain Ellie was gone and out of earshot, the blonde rounded on him. She crossed her arms over her chest and stared down the still-smirking NSA agent. "What did you say to her, Casey?"

He started weaponing down, taking his time before responding, the clink of his trusty Sig making contact with the table the only sound breaking the silence. He could feel Sarah's unwavering gaze upon him as he continued slowly and deliberately unloading his personal artillery.

After he set the last grenade on the table, he turned and faced his partner, his blue eyes locking with hers. "I gave Dr. Bartowski a little something to think about."

Present Day…

The rich aroma of slow-cooked beef filled the air as Ellie made final dinner preparations. The table was already set, and she poked her head in the fridge, checking to see if the whipped cream she had spun up earlier was still light and airy. Satisfied with the height of the creamy white peaks, she shut the refrigerator door, just as the doorbell rang. She glanced at the clock on the microwave and smiled. Six o'clock on the dot, punctual as always.

She barely got the door open before his hands were on her hips hauling her up against the length of his body. The stubble along his jaw rasped against the softness of her cheek as he murmured against her ear "Quick, kiss me! Mrs. Reynolds is watching." Mrs. Reynolds was the elderly, eagle-eyed gossip monger that lived catty-corner from Ellie across the courtyard. If witnessed by Mrs. Reynolds, news of John and Ellie's public display of affection would be telegraphed along the rumor mill in mere minutes, further solidifying their cover.

Instead of the usual firm, yet brief kiss on the lips that she usually gave him in public, she reached up, encircled his neck, threaded her fingers through his hair and pulled his head down. He couldn't stop the momentum of his mouth crashing down on hers with bruising force, and she made it very obvious that she didn't want him to. Before he even had a chance to react, her mouth was open under his, and she wrapped her lips around his tongue, sucking it into her mouth.

Well, damn, this was new, but he sure as hell was going to go with it. He wedged a size 15 black boot between the scarlet sling-backed peek-a-boo heels covering her feet, coaxing her legs apart with his knee.

Ellie held on and continued to kiss him, the extra height afforded by her heels easily allowing her to straddle his thigh. She had a thing for men in cargos, him being her favorite model. He had to know they got her riled, since she'd been caught, more than once, enjoying the way he wore them on missions. The midnight black pants, which he wore tonight, were no exception. The ruby-red halter dress ended abruptly at mid thigh, and the button on the pocket topping the center of his thigh rubbed against her sensitive inner flesh as she gripped his rock-hard muscle between her legs.

Christ! He could feel the heat radiating from her thinly-veiled core, the friction building and threatening to ignite as she unashamedly started rocking softly against him. His hunger for her started to spiral out of control as he imagined what color shreds her panties would make as he tore them off with his teeth.

She drove him to the edge of reason, and for a man like him, that made the situation infinitely more dangerous. He had to get her inside before he took her right there, against the door frame, in front of God, country and the currently slack-jawed Mrs. Reynolds.

He growled into her mouth, and his fingers dug into the swell of her hips, as he half carried, half dragged her into the condo. Ten fingertip-shaped bruises were already starting to blossom against the curvy flesh. After crossing the threshold, he turned them 180 degrees and reached down and around, cupping her rounded bottom, keeping her sealed against him as he lifted her up.

She instinctively wrapped her legs around his waist, the fabric of her dress bunching around her hips. The wood felt cool against her bare back, the impact of John pinning her against the door with his bulk causing it to slam shut.

Just as she began to consider the beauty of asphyxiating this way, he broke the kiss, allowing them to greedily fill their lungs with air. Her respite was short-lived, and he showed no mercy. She was still breathing raggedly, drawing in copious amounts of oxygen, when his mouth was on hers again. His tongue licked along hers with long, deep strokes.

John had let this continue far beyond what was appropriate, but he really didn't give a fuck. Ellie tasted better than anything he had ever sampled, and she fit against him so sweet and right. She made him ache in the best and worst possible way. He wanted to feast on her forever. She was making the sexiest little mewling sounds quietly into his mouth, and he was about to do something he couldn't take back. He set out to discover what she would sound like at full volume.

She had never been this physically close to John, even when they previously "pretended" to be a couple. Things were not going to be the same again after tonight. She refused to let them return to their asset/handler relationship, especially not after getting a taste of what it felt like when John let his guard down and allowed himself to succumb to their shared attraction.

She felt him swell, growing large and hard against her belly. If he later claimed he was doing all of this for their cover and in the name of the overall mission, she would call him out with surgical precision. For now, she fully intended to enjoy being wrapped around him. The man was as solid as a boulder and felt burning hot against her bare skin and the thinly knitted fabric of her dress. If their first time together ended up being against the front door, so be it. She wanted John Casey, and she was going to have him.

He had plenty of control left. He would be able to stop well before he buried himself balls deep inside of her and jack hammered her into the front door.

A single bead of sweat trailed down the column of her throat, and he diligently tracked it with the tip of his tongue, licking in its wake. He paused briefly in his pursuit to place a hot, open-mouthed kiss at the hollow of her throat and felt her flushed skin shift deliciously across his mouth as she swallowed a groan. Her moan of pleasure vibrated against his lips in belated response. He continued hunting the droplet, pressing kisses along the slight cleft between her breasts, tracing the contours of exposed skin with his tongue.

He wanted his hands to follow everywhere his mouth had been, but they were occupied at the moment with her beautiful backside. During his life he had faced worse dilemmas, so he gave her a gentle squeeze and kept his hands anchored right where they were.

She arched against him, offering more of herself as she felt his teeth nip hungrily along her neck. His thumb, which had been languidly tracing along the outer edge of her panties, dipped under the lacy fabric. Rough and calloused met soft and bare. A strangled "John" caught in her throat as he skimmed across her hip bone.

He was exploring the intriguing ridge of her clavicle, outlining it with his tongue, when he heard her attempt to say his name. "Mmmm hmmmm," he hummed against the pulse point throbbing wildly in her throat, latching on and sucking. The rest of his fingers, not to be outdone, slipped beneath her panties, and he cupped her in his palms.

As her thighs squeezed his waist and her heels dug into the small of his back, he sank his teeth into the warm, sun-kissed skin of her shoulder, his control in tatters. She cried out as sensations of pleasure, gilded with a whisper of pain, coursed through her. He felt her shudder around him as he soothed the hurt on her shoulder.

He growled low in his throat. It couldn't be. While soft and almost imperceptible at first, the intensity and volume of the knocking increased and was followed by the insistent ringing of the doorbell. "Ignore it," she instructed, still breathless. But, the persistence of the person on the other side of the door continued to build, commanding attention, or his fist. He firmly decided on the later as he felt Ellie unwrap her legs from his waist and slide slowly and bonelessly down his torso. She held on to his shoulders for a moment until she was sure she was able to stand on her own.

She stepped aside, and he looked out the peephole. His growl intensified.

"Who is it, John?"

"Someone who obviously hasn't learned that curiosity killed the cat," he ground out from between clenched teeth.

Sharp cracking sounds filled the silence that hung in the air as he squeezed his knuckles before opening the door.

"Oh, hello, dear," the tiny woman greeted him, smiling as she craned her head to look up at Casey, her watery brown eyes enormous behind her bifocals.

He kept his best "respect your elders" smile firmly in place. He wasn't in the habit of killing nosey old ladies, but if this continued much longer, he might be forced to make an exception.

"Hello, Mrs. Reynolds," he replied, gazing down at her, crossing his arms over his chest and widening his stance, preventing her from peering around him and peeking into the condo.

"I was just coming back from checking the mail when I noticed a bag sitting outside Dr. Bartowski's door," she said, pointing at Casey's black duffle bag. "I didn't want any of those hooligans that sometimes come through here, to steal it. You know, that big balding blond man and his strange little dark-haired friend."

Casey's smile turned a bit more genuine and he allowed a bit of forgiveness for the older woman to enter his heart. "That's very kind of you, Mrs. Reynolds," Casey thanked her, picking up the bag. "Forgive me, but Ellie and I were just about to sit down to dinner. Have a good evening, ma'am."

"Enjoy your dinner, Mr. Casey," she winked and walked across the courtyard to her apartment with a spry spring in her step.

A long sigh escaped Casey's lungs as he walked back into the condo and quietly closed the door behind him, leaning against it as he set the duffle bag at his feet.

His back had been turned, talking to Mrs. Reynolds for less than five minutes, and Ellie had already plated and set out dinner.

She walked toward him, her usual sweet smile on her face. "Ellie, I –," an unformed explanation or excuse, he wasn't sure which, was cut short as she took his hand and led him toward the table.

"Come and eat while everything is still warm." She looked pointedly at his overnight bag. "We can have more fun, later."

He was rendered speechless as he sat at the table and felt extremely aroused. He had always been the hunter, but he was fairly certain he was going to enjoy being the prey.

TBC

Author's Note: In part two, Casey and Ellie enjoy a delectable dinner for two, followed by bedtime. Will they actually sleep? Doubtful.