A/N: I have always loved the bond between Carson and Mary and I adore the way he talks about the little experience he had with her when she was a little girl when he talks with Mrs Hughes in season 2. I feel he had such a hand in her upbringing - more of a hand than even Robert did - and I feel like he was her confidant through so much of her life so I may do more little one shots like this with them at the centre if you guys like this! Happy reading.

He returns the final piece of silver to the cabinet after polishing it until he can see his reflection and then turns the key in the lock, securing it for the night. Stifling a yawn, he passes a hand over his hair before turning on his heel and making his way out of the room and back out into the little candlelit passage. He sees Mrs Albright leaving her study, shutting the door behind her, and he smiles when she looks at him.

"Goodnight, Mrs Albright."

"Goodnight, Mr Carson."

After their brief exchange, her heels click down the passage as she heads for the stairs that lead to the sleeping quarters at the top of the house and he turns to make his way to his own study. He knows that it has already gone midnight and he should probably be heading to bed himself, but this has become a part of his routine. Returning to his study at the end of the night and just sitting there for a time, his eyes closed, revelling in the delightful silence that has fallen over the quarters and reflecting on his work day.

Once he has reached his study and closed the door behind him, he walks over to the small table in the corner and pours himself a small glass of port before drinking it and turning to his desk. He sits down in his chair, clasps his hands in his lap, and just as he settles back and begins to close his eyes there is a light knock on his door. Honestly, it was so light he's unsure it was even a knock at all initially, but then he hears it again and he calls out for whoever it is to enter. It takes a moment or two, but the doorknob eventually turns and when the door opens he sees Miss Mary standing in the passage in her nightgown.

He hasn't the slightest notion what she is doing awake at this hour, nor how she bypassed the nanny on duty, but, then again, he has known this little girl long enough now to know never to underestimate her. She may only be four, but he has no doubt that she could give the king a run for his money. Turning in his chair so he is facing her, he gives her a smile which she returns before she pads into the room, her beloved teddy in one hand and tea-set in the other, and makes her way towards him. "Mr Carson," She takes a breath, a soft curl escaping her braid and slipping onto her forehead. "I've decided to run away."

"Have you now?" He quirks an eyebrow.

"Mhm," She nods. "I have the important things, my bear and my tea-set, but I might get hungry and so I wonder if I might take some of the silver to sell. Papa has so much of it, he won't mind if some is gone."

It takes everything in him to keep from chuckling. He can tell by her expression that she is dead serious about this, but the thought of this girl, so small she can only just about see over his desk, attempting to pawn His Lordship's silver is rather amusing. He sits there for a moment, his brain working to figure out a response, before he looks at her current state of dress again. "Well, I think you might end up getting a bit cold if you go out there now," He says. "Do you think you can manage a warm drink before you go?"

She glances at the clock and sighs deeply. "I suppose I do have a little time. And I am quite thirsty."

"Grand," He stands from his chair then and holds out a hand, letting her give him her tea-set for him to carry before she takes his free hand in hers and he leads her from the study. "So, some hot chocolate?"

"Hot chocolate is my favourite!" She beams. "You're very clever, Carson. Nearly as clever as me."

"I take that as very high praise, Miss Mary." He assures her while leading her to the kitchens, the two of them chuckling as they enter before he walks her over to the table and pulls out a chair so that she can sit. She sits her teddy bear down on the table and he carefully places her tea set next to it, powerless to resist smoothing a hand over her dark curls before he heads over to the stove so he can start making a drink for her. He glances over his shoulder at her every now and again while making her chocolate, just to ensure she is doing okay, and he smiles as he watches her play with her bear and talk quietly to him.

It only takes him a couple minutes to make her drink, making himself a cup of tea at the same time, and before he knows it he is making his way back over to her and setting her hot chocolate down in front of her. She thanks him gently, dropping her teddy bear so she can take the cup in her hands, and he sips at his cup of tea while sitting down in the chair at her side. "So," He clears his throat as he sets both the teacup and saucer down on the table, leaning back in his chair and looking at her. "You're really going?"

"Mhm." She hums into her drink, big brown eyes looking back at him over the rim of the cup.

"May I ask why?" He inquires.

She lets out the deepest huff and reaches out to place her cup back down on the table, licking away the froth on her upper lip, and she plays with the hem of her nightgown as she thinks for a moment. "Mama and Papa don't like me as much anymore, I don't think," She tells him. "Mama used to play with just me, but then Edith came and she spent all the time with her when we came downstairs and I had to be quiet when I played my games. Edith takes all my toys now too and when I get upset, Mama just says I need to share my toys with her, but she doesn't tell her to share hers with me. Edith always ruins everything."

"Ah, I see…" He nods, understanding her.

"And then Mama and Papa needed to have another baby, so now they spend even less time with me," She pouts, crossing her arms over her chest. "I like the new baby more than I like Edith though. I think she likes me best too, really, because she always smiles when I play with her but she just cries if Edith does," She smiles for a second at that, but then her face falls again. "I think…I think I just get in the way now though. Mama and Papa are always busy with Edith and Sybil, so I don't play with them like I used to, and Mama gets upset with me if I get upset with Edith. If I run away, then I won't upset her anymore."

He is silent for a moment, reaching for his tea and taking another sip, before he moves closer to her on his chair. "Can I be honest with you about something?" He asks, taking her tiny hand warmly in his own.

"Okay." She replies.

"I actually think Her Ladyship would be more upset if you ran away. His Lordship too." He tells her.

"You do?"

"Of course. They won't say it themselves, very few people do, but they love you very much," He reveals. "I think you might even be more special to them than Miss Edith or Miss Sybil because you were here before either of them. I remember the night you were born. His Lordship was the proudest I have ever seen him and that was all because of you. Does that sound like somebody who would be pleased if he woke up tomorrow to find you had run away? Her Ladyship, too, do you think she would be? Honestly?"

She thinks his words over for a second before slowly shaking her head. "I think they would be sad."

"I think they would be too," He agrees. "I also imagine it would make things somewhat awkward for His Lordship because he would have a lot of explaining to do, so how about I make you a little deal, hmm?"

"I'm listening…" She gives him a look that makes him chuckle.

"How about we get you back upstairs to bed and, tomorrow, I will give you sixpence to spend when you next head into the village? You could buy some sweets or something nice like that. What do you think?"

Her face breaks out into the most angelic smile, the excitement plain to see, before she suddenly turns a little more serious and clears her throat quietly. "Very well, but you must be sure to charge me interest."

"Naturally," Is his response as he stands from his chair again before lifting her out of her own, perching her on his hip, and handing her teddy bear to her again before carrying her out of the kitchen. He walks through the quarters, navigating his way to the staircase that will lead them up to the corridor on which the night nursery is located, and once they make it to the corridor he carries her quietly down it before opening the door and stepping inside. Nanny Willis has fallen asleep in the rocking chair near the fire, undoubtedly how Miss Mary succeeded in creeping out of the nursery undetected, and he rolls his eyes.

Deciding against waking her and giving her a lecture on unprofessionalism, for he is far too tired at this point to do so, he simply readjusts his hold on the girl and carries her back to her bed near the window. He sits her down at the foot of it as he pulls back the covers and plumps the pillow a little, and then he watches her crawl her way up the bed before she lays down and he covers her with the quilt, tucking it around her. "Promise me you're going to stay here for the rest of the night when I leave?" He asks her.

"Promise," She says sleepily, snuggling down under the covers with her bear. Her eyes slowly begin to fall closed then, but just before she succeeds in slipping under they open again and she gasps gently. "Carson! I know what you could charge me for interest." She tells him, her sweet brown eyes sparkling.

"Do you? Now what could that be?" He inquires.

Without words, she leans in and gives him the softest kiss on the cheek. "There."

He feels warmth pool in his chest as she settles back again, the deep fondness he has for this precious little being only deepening as he watches her get comfortable. "You know; I think that is a fine solution."

She giggles, wrapping her arms around her teddy bear. "Thank you for being my friend, Carson."

"Thank you for being mine, Miss Mary," He brushes a curl behind her ear. "Now, you need some sleep."

She hums in agreement, her eyes slipping closed once more. "Goodnight."

"Goodnight." He echoes before he stands from the bed and makes his way back across the room to the door, stepping silently out into the corridor once again and closing the door behind him. He feels more than confident now that she's not going to go running around the house again tonight, knowing now that she is far from a burden on her parents and that she has no need to feel as such. No, he thinks, running a hand through his hair as he starts making his way to bed, she is more special than she even realises.

She is a wonderful, intelligent little girl and he can already tell she is going to go on to do great things.

Great things, indeed.

A/N: Thank you so much for taking the time to read! I really hope you liked reading this little one-shot as much as I liked writing it. Little Lady Mary is so fun to write for, so I may have to write more. I would love for you to leave a little review if you have the time to let me know what you thought. Thank you again!