A/N: Thanks to my friend jesmel for the beta work!

Disclaimer: I don't own Mark, Lexie, or any other fictional doctors.

Auld Lang Syne

Malls are malls, no matter where you go, particularly near Christmas with the bright lights, throngs of people, and piped in holiday music playing at a volume that's just a little too loud. It's exhilarating and exhausting all at the same time. Mainly exhausting though, Lexie Gray thinks as she slows down to examine the handbags on display in the Coach window. Especially when you've just come off a five hour plane ride, which was preceded by a double shift, and you haven't even started your Christmas shopping yet because you didn't want to have to buy everyone gifts small enough to fit in your carry-on bag.

She takes a couple of steps into the accessories store before reconsidering and backing out again, the thought of fighting through the crush of people in the store making her a little short of breath. Loosening her stripy wool scarf as she turns around, she decides maybe a shopping list would be a good idea and she goes off in search of a place to sit down, just for a minute while she gathers her bearings.

This particular mall is a made up of a veritable maze of corridors and escalators, all converging on a centre atrium with a fountain and a skylight and a kiosk selling overpriced beverages and oversized pastries. Lexie purchases a hot chocolate topped with whipped cream and crushed candy cane bits and scans the crowded seating area for somewhere to rest her weary bones. Oh, and make a list. Right.

Just past the far end of the seating area her eyes alight on Santa Claus sitting on a big red throne next to a plastic Christmas tree adorned with flashing red and green lights. A teenage girl dressed as an elf is escorting children to his lap while a man sporting reindeer antlers snaps pictures with a Polaroid camera supported by a rickety looking tripod. A little boy of about five is shaking his curly brown head at the elf girl, finger firmly inserted in his mouth. She crouches down, whispers something in his ear and then extends a hand to him. Seemingly convinced, he takes her hand and allows himself to be led him over to Santa. Lexie grins and makes her way over to a small vacant table for two just off to the side of Santa's throne.

Depositing a bag containing the one present she's managed to buy thus far (a sweater for Derek, selected based on detailed instructions from Meredith) on the floor beside the table, she sinks gratefully into the chair. Lifting her cup of hot chocolate to her mouth, she inhales deeply from the sweet minty chocolate aroma before taking a careful sip. Upon ascertaining it's cool enough to not burn her mouth, she takes a bigger sip followed by what could only be described as a gulp. It's delicious, possibly the best hot chocolate she's ever tasted and she has tasted one heck of a lot of hot chocolate in her thirty years on this earth. She very nearly moans aloud from the pleasure of it all.

And that's when she sees him.

He's seated just one table over, dressed in his familiar battered black leather jacket with his grey-brown hair curling over his collar. He is focused on watching Santa with far more intensity than makes sense to her. The hot chocolate turns to liquid cement in her throat and she begins to cough and sputter, attracting the attention of everyone in the immediate vicinity. His head whips around.

"Lexie?" he asks, incredulous. Tears are streaming from her eyes and she manages to nod while she continues to cough. "Are you okay?" He looks stunned. Feeling pretty stunned herself, she holds up one finger and then takes a couple more sips of her drink until her coughing subsides.

"Mark," she says when she's pulled herself back together. "Um. Hi. How are you?"

"All right," he says, rising, taking two steps and then sliding into the vacant seat across from her. He hands her a tissue he seems to have pulled out of thin air. "What are you doing here?"

"Sh..shopping," she stutters, her throat still threatening to erupt into another coughing fit at the slightest of provocations. "Christmas shopping." She dabs the tissue at her teary eyes.

"Obviously." He's not even looking at her anymore; his gaze is back on Santa. "But I meant here in Seattle."

"Oh." Of course he did. "I'm, ah. I'm staying with Meredith. And Derek. I'm staying with Meredith and Derek. For the holidays," she clarifies.

"The holidays," he repeats, turning his head to meet her eyes. "You'll be there for Christmas dinner," he says, and it's not so much a question as a statement and he doesn't seem to be addressing it to her so much as himself. She tries not to squirm under the intensity of his stare. Tries, and fails miserably because the look he's subjecting her to wouldn't be out of place coming from a witness examining suspects in a police line-up. She feels like she should apologize for something, but she's not sure for what. Disturbing his afternoon by her very existence perhaps? She picks up her hot chocolate and takes another sip.

Well he's not the only one disturbed. It's been five years since she last saw him. Five years of surgeries and rounds and dates and boyfriends and breakups and laughter and tears. Five years of growing up and five years of convincing herself that she was over him. She knew she would most likely see him on this trip, he's her brother-in-law's best friend after all, but she had honestly thought it would be fine. They were only together for a year – barely any time at all. And it was so, so, long ago and really, she was a completely different person now. A person with a full life and a great career and even a nice guy who, given a couple more good dates, might possibly turn into her boyfriend. She had really thought it would be fine.

Yeah. She knows now how wrong she was.

It's not fine. She is not fine. God, not even a little bit. What she is, is freaked the hell out. She should get up, right now, and go back to the airport and fly straight back home to Boston where it's safe. Meredith would just have to understand. She just can't be here; she can't even breathe around him. She pulls at her the scarf around her neck until it's hanging loosely around her shoulders.

A little voice shouting, "Grampie! Grampie!" startles her out of her internal drama. The reluctant little boy with the brown curls she'd noticed earlier comes racing over, waving a Polaroid photo, and launching himself at Mark. "Santa's going to bring me a fire truck!"

Mark is slow to react, but when he does, his face splits into a broad grin. "Good to know, sport. Good to know," he says as he scoops the boy up onto his knee. Only then do the pieces fall into place for her. She can't believe it took her this long to clue in because, side by side, the resemblance is really quite remarkable.

"Your grandson," she says quietly. "He's beautiful."

Mark nods his acknowledgement. "I think so."

"So Sloan is..." she begins, looking around to see if she can spot Mark's daughter anywhere in the vicinity.

He shrugs. "Not here," is all he says and something about the stony look on his face makes her think better of pursuing that particular topic of conversation any further.

She notices the little boy watching at her from his spot on Mark's lap. "Hi there," she says to him. "What's your name?"

He looks uncertainly at his grandfather, who nods and says, "Tell the lady your name, sport."

"Samuel Sloan Riley," the boy recites at breakneck speed.

Mark ruffles his hair and adds for Lexie's benefit, "Sammy. His name is Sammy."

"It's nice to meet you, Sammy. I'm Lexie."

The boy smiles shyly at her for a second before turning back to Mark. "Grampie, can we go home now?"

Mark is silent for a moment. Lexie watches him guardedly, hoping he acquiesces to the boy's wishes and leaves her alone so she can start breathing again. Yes, that's what you hope, a small voice chides. Self-deception, thy name is Lexie.

Long seconds pass in silence until Sammy pipes up again, tugging on Mark's arm. "Grampieeeee, come on, I'm hungry!"

"Oh. Yeah, I guess we'd better be heading home." He sounds almost...disappointed? That can't be right. She looks down at the table as he stands up, not wanting to watch him walk away.

"Lex." His voice comes from above her. She looks up to find him examining her again, but this time his expression looks much less police witness-y and more like a man looking at a woman. "You look good."

"Oh." She blushes the colour of Santa's sleigh. "Um. Thanks. So do you." And he does too. Damn it. This would be easier if he'd gotten fat or lost all his hair.

"So, I guess I'll see you at the Shepherds' for Christmas?"

"Uh, yeah. I'll be there." She smiles tentatively at him, and when he returns it with his patented Mark Sloan Sex God grin, that's when she knows she's in trouble. Serious. Freaking. Trouble.

It takes her another fifteen minutes to finish her hot chocolate, eat the honey dipped cruller she buys to settle her nerves and put together a shopping list. There are an awful lot of gift cards on the list and she hopes her friends and family are subscribers to the 'it's the thought that counts' school of gifting because she really, really needs to get out of there. Meredith had better have a bottle of tequila stashed somewhere in the house.

When she rises and leans down to pick up her purse and shopping bag, she makes a discovery. Face down on the floor under the table is a Polaroid photo of a curly haired boy with a shy smile sitting on Santa's knee. After pausing to add one more name to the bottom of her list, she slips the abandoned Polaroid into her purse and heads back down the hall into the madness that is the mall on the twenty-third of December.