A/N: This is the prequel to Chuck and Sarah VS. the Bunker, and really, the idea that first got me writing FanFiction. The exact nature of the 'Alternative' in AU should become apparent, fairly quickly.

This first Chapter sets up the major change from canon.

Edit: reader Jimmy noticed that I used the wrong AFB in this chapter. I was visiting my sister and we drove past Hickam Air Force Base, and it oozed into my brain when I wrote this. I have made the proper change.

Chapter 1: The Windup

Castle, just after Chuck downloaded Intersect 2.0

"We run away and never look back."

"Sarah..."

"Will you run away with me?"

He started to shake his head, not to say no, just in disbelief. "Yeah."

"Go to the training facility in Prague for now, meet me at the train station in three weeks."

She hugged him, and then it was a whirlwind of SUVs and planes. It was only hours later, on the Gulfstream crossing the country, when he checked his back pocket and found the note.

Castle bugged,

Need to talk privately before Prague.

Newsarama Account: CBSW1980

PW: pineapple

Use as final line of communication

Memorize and Destroy note.

"What'cha got there moron? Love letter?" Casey said, leaning over the seat in front of Chuck. "No don't tell me. I really don't want to hear any of the gruesome details."

"Thanks for the vote of confidence, Casey. Its just a note from Morgan reminding me to return a game I borrowed. I forgot I had it." Chuck said, and stuffed the note in his pocket.

Casey grunted, but went back to his seat. Chuck frowned. There wasn't a number for that grunt. Once the Colonel wasn't looking, he took the note back out, crumpled it in his fist and waited, his palm sweat hopefully smudging the ink. He was certainly nervous enough. Chuck glanced around the cabin a touch furtive, hopefully without alerting either of the NSA agents.

Nobody so much as looked up from their crosswords or their newspapers, or their paperbacks when Chuck stood and made his way aft to the bathroom. With the door closed, he opened his hand and smeared the note around on his sweaty palm, waited a minute or so, flushed and held the note under the sink. After he washed the note, he crumpled the soggy paper into a tiny little ball and then twisted the ball apart. The fibers gave way and there was no possible way to reconstruct the note, so Chuck tossed it in the toilet, dried his hands and went back out to his seat.

Chuck couldn't quite wrap his head around what game Sarah was playing. Did she want to run away with him or not? He was becoming frustrated, but tried not to show it. After a fruitless attempt to engage either of the NSA agents in conversation, to Casey's evident amusement, Chuck just sat in his seat and tried to sleep. He actually managed a couple hours.

On the tarmac at Andrews Air Force Base in DC, Chuck turned to Casey. "Well. Now what?"

"We head over to the BOQ, and get some sleep. Next military flight to Prague is tomorrow morning."

"BOQ?" Chuck said.

"Bachelor Officer's Quarters." Casey said. "I'm a Colonel, and you're whatever it is you are, so we're set up pretty good. Get a good night's sleep and off to Prague we go."

"I slept on the plane."

"Sounds like poor decision making on your part."

Chuck grumbled under his breath and Casey laughed. A Staff sergeant drove up in a Jeep. "Colonel Casey? Major Carmichael? I'm your ride."

"Major Carmichael?" Chuck whispered, incredulous.

"Just go with it, Moron." Casey said, throwing his rucksack into the back of the jeep.

The BOQ that the Air Force assigned for Chuck's use was a small two story house. The pair of NSA agents that had been shadowing him since backup had found them in the intersect room back in LA followed him into the house. One of them immediately laid down on the couch, the other sat at the kitchen table and started dealing himself a game of solitaire. Chuck frowned, and the card-playing NSA agent finally deigned to speak to him. "You need anything give a holler. We've got a couple Air Force M.P.s watching the house front and back, they can run and get you some food or something."

"Pizza sounds good."

Chuck woke up in the dark with a hand across his mouth. "Shh... Don't freak out." He turned and peered into the darkness. Starlight coming in the window framed a halo of luscious blond hair around a familiar face.

"Sarah?" Chuck whispered. "How did you find me? They took my watch."

"I bugged your chucks when we stopped at the motel in Barstow two nights ago." Sarah said. "Think I'm just going to let you run off on your own?"

"Shh." Chuck hissed. "Keep your voice down. There's a bunch of guys downstairs."

Sarah grinned. "I know. I had to climb the trellis while the M.P. had his back turned."

"Is it safe to talk?" Chuck asked.

Sarah put her head down on Chuck's chest and sighed. "Just keep whispering. I checked for bugs, once I got up here, but better safe than sorry."

"So, your note was very cryptic." Chuck whispered. "You think they heard us talking in Castle?"

"They showed us video, complete with audio, of just about every private conversation we thought we'd ever had during the 49B. Of course they were watching. And they'll be watching in Prague at the train station. That's why we can't run. At least not yet."

"Sarah. About that. I'm— what about Ellie and Awesome and Morgan? If we ran, I could never see them again."

"I know. It's not a perfect solution. It's not even a good solution. But, I know what the CIA and the NSA are going to want you to be. What they're going to turn you into."

"A real spy, right? What's wrong with that."

"No. Chuck. They're going to try to turn you into Casey. A cold remorseless killer."

Chuck half sat up, dislodging Sarah from her spot. "What!" Chuck said.

"Keep your voice down." Sarah hissed. "I know you don't want that, but that's what they'll try to do."

"You really think I'll turn into Casey, completely shut down emotionally?"

"I'm scared they might get you there. Eventually." Sarah said.

"Even with you there to keep me... you know, me?"

"I don't think they're going to let me. Be there..."

"What do you mean, you're part of the team, I'd never be able to function without you."

"And that's exactly why they're going to try to break us up." Sarah said. "I'm horribly compromised as a handler, and Beckman knows it, Casey knows it. You turning into a full Agent isn't going to change that. Protocol is protocol. Chuck, this is just the way it is. They don't let cops who are dating stay in the same precinct." She shrugged. "I mean. I could request a closer posting, but the closest CIA post is Mexico city at the embassy, and that's Diplomatic cover, not the kind of work I'm used to or that they'll be wanting either of us to do."

"Long distance relationships never work. So then we can't be together unless we run away?"

"Not openly. I'm sorry. There was no way to talk about it beforehand. We need to stage a breakup or they'll break us up. That's what Prague is for. Once its obvious we're no longer together, Beckman will have no reason to try to split us up in the first place, so she won't have to reassign me, at least for a while."

"What do you mean 'a while?'"

"I mean, that when you get to be a 'real' agent, they're going to want you to operate solo. That's what this new intersect is designed for."

"So hang on. Are we really breaking up?"

"Not on your life." Sarah growled. "I don't commit treason for just anyone. That we got away with it is beside the point."

"If we're not breaking up, wait. We're going to be secret undercover dating?"

"Like I said. It's not a perfect plan." Sarah said, leaning on one elbow. "Anyway, if you need to get me a message save it as a PM on that Newsarama account I gave you. That's our last line of communication. You never tell anyone about that account, under any circumstances. Just be sure you don't use my name, Beckman's name, any keyword that could raise flags in Echelon. And don't send anything from the account, and don't post anything on the boards. From that account. You log on to the website often enough on your main account it shouldn't be suspicious."

"I figured it was going to be something like that." Chuck said. "Anyway. You came all the way to DC to tell me that? I could have figured it out on my own."

Sarah shrugged. "I also got you a present." She dug in her purse.

"You didn't have to get me anything." She glared at him out of the corner of her eye, with a small grin, and handed it over. "A cell phone. Why do I need a cell phone? I already have a cell phone." Chuck quirked an eyebrow. "Is it a super-secret spy-phone?"

"It's a burner." Sarah explained. "Pre-paid, anonymous. I'll keep refilling it for you. But its only for emergencies. If we use the voice function, we'll eventually get spit out of NSA's echelon system's voice recognition, and then have to ditch them. Then when you get a new number, put it in a PM. There's a pretty quick cipher I can teach you, for another layer of security."

"So, no voice. Can I text you?"

"As long as you don't use any names, or any place names, or anything incriminating. Look, again, just steer clear of echelon keywords, and I don't see a problem with it." Sarah said and lay back. She sighed. "I should probably go. I've already been off the grid for six hours. Just remember, we need to sell it in Prague." Sarah stood abruptly and took a step toward the window.

"Hang on, hang on." Chuck said, making a grab for the hem of her coat. Sarah sat back down on the side of the bed. "So, as long as I don't use your name, or my name, I could text you to say..." He leaned in and whispered. Sarah's eyes went wide and she smacked him in the chest.

"Chuck!" She hissed, blushing crimson. But then she thought about it, and Chuck grinned, which only made it worse, because he obviously knew she was thinking about it.

"So, that's a yes on the sexting at least." Chuck said.

Sarah pouted briefly. "Don't use that word. It's tacky. I almost forgot. My burner is speed dial #1. You don't put any other numbers in it. You don't call anyone else on it, ever. Clear?"

"Yes, Agent Walker. Perfectly."

"Don't call me that when we're not working."

Chuck winced and sat up. "Okay, Sarah. I'm sorry." He reached out and his hand found hers. "It won't happen again."

Sarah sighed and laced their fingers together, squeezed his hand. "It better not." She shrugged. "Anyway, about that phone. You need to come up with a hiding place, and keep it turned off, with the battery removed if you're not using it. If you go on a mission, remove the SIM card and hide it separately from the phone. They're going to start teaching you some of this stuff, but you need to be ahead of the curve. I'll text you some tips if you're having trouble."

Chuck smiled sadly and brought her hand up to his lips. "Normal's overrated anyway."

Sarah shivered at the touch. "No it isn't." She whispered, and glanced at her watch. "I need to go. Guard shift changes in a couple minutes. That's my window to slip off the base undetected."

"Stay." Chuck whispered.

Sarah looked down briefly and then grinned at him. "That's a really bad idea, Chuck."

"I'm not— I won't try anything. I promise." Chuck said.

Sarah's shoulders shook in laughter. "Goof. I know that. Your NSA guards could walk in on us, and then I'd be reassigned so fast both ourheads would spin. If they didn't try to throw me in jail. I suppose I am technically trespassing on government property right now."

"I'm going to slip up eventually." Chuck said. "I can't pretend not to be in love with you forever. You know that? Right? Nobody's that good an actor."

"I know." Sarah said. "If we are going to run, I need more than three weeks to get us all the way gone, for good."

"But... how long could we last, on the run?" Chuck said. "And I don't know that I could handle that anyway."

"Chuck. I know, okay. This is... I plan. I'm a planner. If you want me in your life... the way I want to be in your life, we need to plan. You..." She grinned crookedly. "You're going to make me say it, aren't you?"

"Not if you don't want to say it, no." Chuck said. "You committed treason for me. If I didn't already know before then, that would have told me."

Sarah frowned, crinkled her nose. "When did you know, then?"

"Stay, and I'll tell you."

Sarah rolled her eyes. "I can't stay long. If I miss this shift change, the next one is in two hours."

"Why Sarah, what are you suggesting?" Chuck waggled his eyebrows, and she laughed softly and wrapped him in a hug.

"Not the Bartowski eyebrow dance." Sarah moaned into his neck. "Anything but that."

"I— my god. I told you I love you." Chuck stammered. "I didn't mean to tell you like that. I had it planned out a little better than that."

"Shh..." She said, putting a finger to his lips. "It was still good to hear. I..."

Chuck kissed the side of her neck. "Still can't say it. And that's fine. When you're ready, not a second before."

"Lie down." Sarah shimmied out of her coat and set the alarm clock, before snuggling in next to him. "This is good. For as long as it lasts. You have me, and that's the truth under all the lies. Is that enough for you? For now?"

Chuck blinked back the beginnings of tears. "Of course. I'm sorry if I made you doubt that... I didn't mean to..."

"Shh..." She whispered again. "We'll figure something out. We always do."

"You didn't answer my question." Chuck said finally. "How long could we stay on the run?"

"If we left from Prague in three weeks and managed to shake the surveillance teams staking the place out?" Sarah asked. She felt Chuck's nod. "I don't know. A year, eighteen months. Two years at the outside, as long as we didn't slip up. They'd be dogging our footsteps the whole time. We'd always be running, always afraid to stay in one place for more than a night or two. But there'd be no doubt we were together."

"Two years isn't a long time."

"We'd be together though." She said. "Its more time than some people get with the one they..." Damn it, she still couldn't say it.

Chuck stroked his fingers through her hair, brushed loose strands off her cheek. He rubbed his thumb gently across her lips. "I know, Sarah. Maybe its me. Maybe I'm just greedy."

"It's not just you." She said, putting her head down and smiling against his chest. "In forty years, I want to be able to grab your ass and gross out our grandkids any time I get the itch."

"I have no problem with that plan. Just don't squeeze too hard and break my hip." Chuck said. "You know how fragile us old fogies can be."

"Uh-huh. I can be gentle." Sarah said into his chest.

Chuck sighed. "How is this going to work? I'm going to have to sell Ellie on the breakup? What about Awesome? He knows things..."

"Everybody, Awesome included." Sarah said. "When— if Casey and Beckman figure this out, it needs to seem like we had a relapse, not like we've been faking the breakup the whole time. That's the only way we can salvage the time to run."

"So now that we're finally, really going out, I can't tell anybody, ever?" Chuck said. "I kind of want to shout it from the rooftops."

"Maybe keep that to a minimum if you want to stay out of a bunker." Sarah murmured. "Are we just going to talk, or are you going to try something?"

"I told you I wasn't going to try anything."

Sarah writhed around so she could look down on him, frowning in disappointment. "I thought you were joking."

"This isn't the most romantic situation to... You know." Chuck said. "I can't tell Morgan, ever?"

"On our twentieth wedding anniversary, you can tell anyone you want if its still bugging you." Sarah said. And then she tensed once she realized what she said.

"Um... we haven't talked about... I... um. This is awkward. You want to get married... I thought we were joking about the grandkids thing. Aren't we moving a little fast?"

"You want to keep it, you're going to have to put a ring on it." Sarah said, poking him in the chest. "We've been in limbo for more than two years. Most couples would at least be discussing it."

"Buh... ha... I..."

Sarah grumbled something under her breath and grabbed a fistful of his shirt and shook him by it. "Snap out of it. Eventually. Eventually, Chuck. Like Ellie is eventually going to have a conniption if we 'break up' and still 'hang out' all the time when we're on missions... and you don't get a new girlfrie—"

"Oh no way. You're not making me get a new cover girlfriend while we're secret under-cover dating." Chuck said heatedly. "That would be too weird, even for us."

"It might become necessary."

"Sarah, come on." Chuck said. "I'm not going to fake cheat on my not-ex-girlfriend that... It's so complicated I can't even figure out how to start to tell you about it. And you're the one person who should understand what I'm—"

"Shhh..." She said again, putting a finger to his lips. "You're babbling. It probably won't even come to that."

"Probably. That's not very reassuring."

"Just shhh... We can figure the rest out later. I just had to make sure we were on the same page for Prague. You're not a very good pillow right now." Sarah said and pulled herself up him, crushed her chest into him and kissed him briefly but passionately. "And you talked me into a nap." She whispered, lips still almost brushing his. "So, shush." Chuck smiled, put his arms around her, and they drifted off.

When he woke, there was just a cold space in the bed where Sarah had been. Chuck had a brief shivering feeling that he had imagined the whole thing. But there on the nightstand, held down by the disposable phone she'd brought him, was a brief note.

Still can't say it. Can't even write it down.

But I'm glad you know. Thank you.

SW

Destroy this note.

Chuck put the note in the sink while he lathered up to shave. Once he got out of the shower the note was completely dissolved and he fished the bits and pieces out into the trash. This was getting ridiculous. He went back into the bedroom and grabbed the burner off the nightstand.

getting tired of destroying your notes

A minute or so passed before Sarah responded.

:(

That was all. Chuck rolled his eyes and started texting back, when there was a pounding on the door, and Casey's voice came through. "Time to wake up, Moron." Chuck slipped the burner in his back pocket and opened the door. Casey jumped back. "Whoa. You're up early."

"I'm excited."

"Well stop it. You're creeping me out. I'm used to you sleeping until noon every chance you get." Casey growled. "You got all your crap? Cleaner team's going to burn everything once we leave."

"That's reassuring." Chuck said, echoing his sentiments from earlier that morning.

"They don't pay me to reassure you, Moron. They pay me to blow stuff up."

"Really. There's an explosives bonus clause in your contract?" Chuck grinned. "That explains so very many things."

Casey grunted. "Shut up, Bartowski."

At least that hadn't changed.

TO BE CONTINUED...