Due to popular demand, this will no longer be a one-shot as was my original intention. Instead, it will continue throughout the entire crossover event. It will be based loosely on what we see on-screen, with some changes and additions to scenes, maybe for a different spin on things.

For the purposes of this story, Mark already knows that Addison is coming back (apparent from chapter one) as well as Derek and presumably the Chief. Nobody else is aware yet, however.

This chapter is mainly to get the timeline of this story back on track, since the first was written before 5.14. It's a bit dry and narrative-ish or a while.

Disclaimer: Grey's Anatomy is the property of Shonda Rhimes and ABC. This writing is for entertainment purposes only and is not for profit.

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The streetlamps are distorted blurs in the too-bright morning sun as Lexie whizzes past them, going much faster than twelve over the speed limit. She passes the sedan in front of her, swearing through clenched teeth as she looks at the digital clock display. Rounds start in five minutes, and she's still about eight away.

She cranks up the radio, blasting a happy pop song. Anything to take her mind away from the sadness she was suddenly carrying.

It wasn't that he said he loved Addison. Of course, it had bothered her a little bit, but it was completely plausible that he had fallen out of it. It happens all the time, she tells herself. She had loved George, right? Okay, bad example. Still, she had reason to believe that his use of the past tense meant it really was the past.

"I loved her," he had said, quiet but as clear as crystal, struggling from the inside out. After that, silence. She knew he wouldn't say anything more. So, slightly dazed and freaked out by the confession, she held him wordlessly until she absolutely had to leave.

"This isn't me running away," she had explained breathlessly, throwing on whatever clothes she happened to grab. "I promised you that." Still frozen on the bed, shell-shocked, head in his hands, he nodded.

Stepping out the door, she said, "I guess I'll see you at the hospital, then?" She looked at him. Nothing. He didn't move a muscle. So, with her stomach churning, she turned and left.

And now she's driving dangerously fast to work, about the encounter the wrath of Cristina Yang. But that's the last thing on her mind right now. She groans and rests her head on the steering wheel as she hits her seventh red light. Stopping only gives her mind more time to dwell on it. She can't stop thinking about it. She'd never seen anything like it before.

As a surgeon, she's had to give bad news to both patients and families. Even though she generally connects well with her patients and can really feel for them, their pain is never exactly her own. She's not as close to her patients as she is to Mark Sloan.

The only other person in this category who has had some kind of total anguish is her father. The grief from her mother's death has turned him into a completely different man, completely unrecognizable to her. This is also nothing like she saw this morning. Mark didn't turn into somebody different. He was every bit as much him as he ever was, just…broken. He was the picture of a broken man in a moment of weakness. Something about it being him and not just some empty shell of him pierced Lexie to the core.

But, as she finally pulls into Seattle Grace Hospital's parking lot only a few minutes late, she decides she's happy he confided in her. Maybe it's a sign that the thing between them was more than sex with only one or two strings attached. Maybe it's something much, much bigger than that.

This thought on the forefront of her mind, she hurries across the asphalt to the entrance. As long as he wants her to be there and to help, she will.

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Some time later, Mark steps out of the hospital elevator and onto the surgical floor. He begins walking, shoulders hunched and collar turned up, to the nurses' station. He glides quickly over the tiled floor, avoiding the gazes of all who pass him. It's just that kind of day, and it's bound to get much worse very soon.

He reaches the counter just as Derek does. Derek looks up from the chart he's been scribbling on, eyes just a little bit brighter than normal. Mark's blood boils for an instant. There's nothing someone having a bad day likes to see more than someone having a good day.

"Good morning," Derek almost singsongs, holding back a smile. Mark grunts a reply, shooting furtive looks ever both shoulders and down the hallways on either side of him. Derek's quick to notice and decode this. He clears his throat, setting the chart down. "If you're looking out for Addison, she's not here. She won't be until tomorrow," he explains, raising his eyebrows at his friend.

"What? Really?" Mark's both bewildered and guilty that that single sentence just liberated him of so much dread and anxiety. He's ashamed of his relief. "But I thought Archer-"

"They needed to take a new CT scan. It's not a glioma. Apparently, it's neurocysticercosis."

Mark's jaw drops. "He's got parasitic cysts in his brain?" Derek nods gravely, and Mark cringes. There are certain things a doctor never becomes less sensitive to.

"And it doesn't look good either." Derek shakes his head. "They're waiting on a report from some doctors in New York, and Addison said they should arrive here early tomorrow." Mark sighs deeply, the glimmer of hope ignited by Derek's first statement extinguished by this one.

But then, like magic, that suspicious and creepy light returns to Derek's ice-blue yes. "You know, she said a thing about babies," he said excitedly. "Like babies were a totally ordinary idea. She's not afraid, she's ready." The goofy grin explodes across his face again, pearly whites totally exposed. As for Mark, he's just giving Derek a dumbfounded look.

"…Addison?"

"No!" Derek rolls his eyes. "Meredith." It's now that Mark notices the black velveteen box in the front pocket of Derek's lab coat.

"Whoa!" he exclaims. "What's that?"

After sweeping the area for Meredith's presence, he shows Mark the beautiful diamond ring, holding it under his coat as if he was hiding a gun or peddling fake Rolexes. "It's my mom's…for Meredith," he says, eyes wide with wonder, like a kid on Christmas. "I'm giving it to her. Soon." Mark really smiles, now, his own misery overshadowed by happiness for his friend.

"When are you going to do it?"

"Do what?"

Derek snaps the box closed in fright as the Chief approaches him and Mark, leaning next to them on the counter. "Shepherd's proposing," Mark states slyly and proudly, like a tattletale first grader. Derek purses his lips and narrows his eyes at Mark, who only smirks in back at him.

"No kidding!" Richard cries, clapping Derek proudly on the shoulder. "Outstanding! How are you going to do it?"

"I don't know, just decided."

Owen hunt passes by, distracted, throwing a greeting in the three men's direction. "Shepherd's proposing," Mark says again, earning another look of contempt from Derek. Owen nods, wide-eyed.

"Congratulations, that's a big step."

Derek takes in a ragged breath. To Owen: "Thank you very much." To Mark, aside: "Are you just going to tell everyone?"

Mark waggles his finger at Derek. "You need advice. Hunt, you ever propose before?"

"Uh, sorry, I'm not the guy to ask. When are you going to do it?"

"Well, more importantly, how am I going to do it?"

"Look, Derek," Mark says calmly, "I'll come over tonight and give you a hand. Trust me; I know what the ladies like." He grins lecherously, since it's what he'd do under any normal circumstance. But, he doesn't feel it this time.

"Fine," Derek gives in begrudgingly. "Just don't tell anyone else, okay?" He raises his dark eyebrows at Mark. "I thought I could trust you." Derek turns on his heel and starts down the hallway.

"Of course you can trust me!" Mark calls after him. Of course, he grimaces immediately. That statement is going to come back to bit him in the ass very soon.

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Lexie steps into the chilly outdoors of the ambulance bay, pulling on a pair of gloves. Meredith is already there waiting for her, playing with one of the sleeves of her yellow trauma gown. Lexie double-steps, scurrying up to her. "Hey," Lexie greets smoothly (for once). She's not quite as jumpy around Meredith as she used to be. "I'm with you today."

"So, uh, what's going on with you and Mark Sloan?" she asks from out of the blue, feigning apathy but not quite hiding the suspicion. Lexie's heart jumps into her throat and her stomach drops. Her first reaction is denial, naturally.

"What? Nothing!" She feels words spill from her mouth without control. Talk about a regression. "What, no, why, why? What did you think is…was?" She looks down, becoming preoccupied with her gown in order to avoid eye contact. One corner of Meredith's mouth pulls upward, unconvinced, and she crosses her arms in front of her chest.

"Well, because you've been on his service for over a week," Meredith points out in only a tiny bit less than an accusation. Lexie takes a deep breath and looks at her. She could tell Meredith right now about Mark and this weight would be off her chest. Why should she wait for Mark to tell Derek? With just a few words, the heavy feeling in her stomach could be taken away. She would feel worlds better; she's terrible with secrets.

Why would Meredith care, anyways? She has no right to tell Lexie who to date. Besides, she barely knew of Lexie's existence until a year ago, and didn't really start almost-caring until much more recently.

Lexie wants to tell her. She almost does. She gets the first word halfway out before her mind brings up an image of Mark's face from this morning, full of pain and guilt. Then, she sees the chain reaction that would occur if she let the secret free. Meredith would freak and tell Derek, sending him into a tirade against Mark. She can't do that to him.

Not today.

So, she makes another excuse.

"Yeah, you know, I'm…I'm really interested in plastics," she babbles. "As a specialty, ah, I'm fascinated." Meredith raises her eyebrows and nods, trying to keep up. "I…I like…f-faces," Lexie finishes lamely, forcing herself to smile.

"Mmhm." Meredith rolls her eyes, smirking as the ambulance backs up towards them.

Meredith knows something's up. It'll reveal itself in due time.

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The day passes. Surgeries are stressful but successful. Some diagnoses are bad; Derek's pregnant patient in particular. But, at the end of the day, they all get to go home.

Or, in the case of Mark and Derek, basically fly home in order to decorate a bedroom with every ridiculous cliché in the book for Derek's "grand gesture" of a proposal. It's definitely better than a rowboat or skywriting.

"This is stupid," Derek declares, defeated and discouraged as he lights the thousandth candle. "It looks like Cupid puked in here. She's gonna hate this."

"What, the flowers?" Mark comments, glancing at the gardenia scattered about the room as he too lights another candle. His eyes linger for a second on the giant heart of rose petals on the bedspread. "Girls love this crap."

"It's cliché." He deadpans in an epiphany. "I'm a cliché. And did we have to get the huge stuffed bear?" He exhales loudly in frustration and points at the toy at the end of the bed. "I mean, I think that kind of thing seems more well-suited for the other Grey, doesn't it?" Derek chuckles.

Mark coughs loudly, and he burns his fingers on the match he's holding, biting back some very vulgar words. Instead, he manages to let out a fake laugh. "Ha ha ha, yeah." A quick subject change. "Clichés became clichés for a reason," he enlightens. "Because they worked."

Suddenly, Lexie's request comes to his mind. He remembers her face when she told him she felt like a dirty little secret, the pout she wore. It did things to him; she makes him think like no woman has before. He wants to make her happy. There's nothing to stop him from telling Derek now. They're alone together, there's nobody to make a scene in front of. He can just tell him and get it over with, like ripping a Band-Aid off.

So, he starts to talk, dancing around the subject. "It's great, isn't it? When you feel so strongly for someone and it's not…not just about the sex? It is…" He pauses, searching for the correct word. "It's true." And he means it. He's close, now. He's close to fulfilling Lexie's request, and it feels good.

Derek stares at him for a long moment before laughing sarcastically. "You should not talk like that."

But now Mark sees how excited and nervous Derek is. He sees how much he's looking forward to tonight with Meredith. His heart sinks. He can't do this to Derek.

Not tonight.

"Yeah, you're right," Mark replies, turning away from him, a hint of sadness making its way into his voice. "Well, you're all set here, I'm gonna leave you to it." He sighs and heads to the door.

"Thanks," Derek replies, preoccupied with one of the rose bulbs. Mark stops in just before the hallway, looking at his best friend.

"Congratulations," he says, genuine and clear. Derek smiles back in appreciation.

But the moment is interrupted by a shrill ringing noise. Derek reaches into his pocket, pulls out his phone, and answers it. "Hello?" His nose wrinkles and his eyes narrow. "Cristina?"

Mark watches as Derek carries out his conversation with Yang. "Oh." He sounds disappointed. "Well, okay. Yeah, I get it. It's for the best." He sighs deeply. "Thanks for the warning. I guess so. Bye." He disconnects the call and glances back at Mark, frowning.

"Uh-oh. What happened?"

"Apparently Cristina told Meredith something her mother had written in one of her diaries that might not make a proposal tonight a good idea." Derek shakes his head, trying to hide his dissatisfaction. "I guess I have to clean up."

"Do you want help?"

"No, I've got it." Derek smiles sadly. "Go ahead home." Mark turns to leave.

"Wait, Mark," Derek calls. Mark stops under the doorframe. "Tomorrow is going to be a hard day. For both of us." They lock eyes, and in that instant, the memories of the problematic past flow between them. "But it'll be okay. Trust me."

After a pause, Mark gives a single nod and departs, leaving Derek to sweep the petals off of the bed.

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It doesn't take Mark long to get back to the Archfield. He trudges up to his room, steps out of his shoes, and lies on the bed, not even bothering to turn the light on. He tries not to think about anything at all, but, of course, the first thing his mind takes him to is Lexie. He runs a hand through his hair, imagining how bad this morning was for her. It had seemed like she was avoiding him at the hospital. Come to think of it, she didn't even say one word to him. His insides go hollow. That would just be the icing on top of the crappy cake of the day.

As if on cue, someone knocks impatiently on the door. Mark slowly gets up to answer it, as if he is moving within a dream. He opens the door and she's standing there, her dark eyes looking up at him, locking with his.

Without a word, she embraces him and kisses him deeply. "I promised," she breathes as she breaks away and walks past him into the room. She picks up the clothes of his that happened to be closets – a collared shirt and cashmere pajama pants – and begins to undress. Mark can do nothing but watch her, entranced, amazed at how even after this morning, they're right back to where it all began.

None of his women ever truly stuck with him through the hard times.

Comfortable in his clothes, she takes him by the hand and pulls him to the bed. "Come on. Let's lay down," she murmurs soothingly. Mark complies readily, holding her close, suddenly comforted. She sighs contentedly, eyes drooping.

There are so many things Mark wants to say to her right now. There are even more that he needs to say. The most important makes its way out first.

"I almost told Derek today," he says, gingerly rubbing his hand on the small of her back. "I got so close. I really tried. But I just couldn't do it." He shakes his head. "Not now. But I promise you, I will." A tiny smile breaks across his lips as he looks at her. He can sense that he's about to cross over into Cliché-land himself, and he doesn't really care.

"I don't want to keep you a secret anymore, Lexie," he says. "I want to tell everyone. I want your friends and mine to know. Shit, I even think I want to shout it from the rooftops." Lexie laughs, her body shaking against his. The sound brings him relief and makes him happier than he's been all day.

"I'll do it as soon as I can," he vows. "Time isn't on our side, Lexie."

"I know." She inhales his scent, happy beyond belief that he's talking again. She feels like she needs to say something about what happened earlier, to clear the air. If there's anything she's learned in the past year, it's not to leave things unsaid.

"About this morning," she begins tentatively, gauging his reaction. He tenses a bit, but not much. Just having her there is like a drug. "I want you to know that what you said is perfectly okay. We all have a past. Like, when I was in third grade," she says, "I threw up in the middle of class. I had my first kiss at thirteen with a boy named Adam Garwood. And this one time…" Her voice drops to a whisper. "I broke a man's penis."

Mark lets out a real laugh, almost a guffaw. Lexie grins up at him. "And I'm going to be here for you, as long as you want me to be," she says, slow and steady, having practiced the speech on the car ride here. "I'm willing to listen to anything you want to tell me, not matter how terrified you think I'll be by it. Starting now."

The next words spill from Mark's mouth before he has a chance to stop them. It's like they were triggered by some kind of involuntary reaction. "Addison's coming to Seattle tomorrow. She needs Derek to operate on her brother."

She's a bit stunned, but, at the same time, not surprised. "Okay. That's…that's good. Thanks for telling me," she says. She's not used to this job.

Derek's words from earlier enter his mind. "Tomorrow is going to be a hard day. For both of us." A hard day for him and Lexie as well. Perhaps even a defining day.

For a few moments, they lie there, breathing together in the darkness and sharing in a moment of peace.

"Is there anything else you want to tell me?" Lexie asks gently and drowsily. "Like I said, completely ready to listen."

Mark is silent for a long while. Lexie figures he's let enough off his chest for today. She closes her eyes and rests against him, ready to succumb to the drowsy feelings.

Then, he speaks. "After Derek left for Seattle, we had a relationship. A real one." He falters for a moment. "She was pregnant. She was going to have my baby." The silence after seems to be a lot more silent than before, providing the obvious conclusion to his thought.

Lexie doesn't know what to say. But Mark seems to be just fine with that.

Thoughts dwelling somewhere on tomorrow, they eventually slip into a restless sleep.

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In what seems like minutes later, Lexie is awakened by a harsh rattling noise coming from across the bed. It takes more than a second for her sleep-muddled mind to realize that it's Mark's cell phone vibrating against the nightstand next to him. The sound only came once, so she decides it's a text message. She rubs her eyes and looks at the clock, which reads 4:48 A.M. It's actually been hours.

"Mark," she rasps. "Mark, your phone." He groans something unintelligible before delving back into sleep. Lexie rolls her eyes and reaches over him, trying not to lean on him too heavily, grabbing the phone from the table. She opens it to the keypad, eyes squinting and watering against the screen's bright light.

When she can finally see the letters, her heart feels like somebody squeezed it and her chest feels like a deflated balloon. She was right; it's a text message. And the name attached to it? Addison.

Against her better judgment, she opens the message. It's riddled with typos probably caused by nerves and preoccupation.

On the way to SGH. derek is going to be ready for archers surgrey when we arirve. archer is in a coma now. not good. i hope i get to see you

Lexie's stomach churns again.

Today is definitely not going to be easy.