Many thanks to the amazing mrspencil for Brit-picking, and to the wonderful Wynsom for beta-ing and for giving this work the perfect title. You ladies keep me right!

This is based on happenings and conversations with my four-year-old grandson and my 18-month-old granddaughter. My grandson is quiet and contemplative, verbally advanced, serious-minded with a scientific bent. My granddaughter is loud and exuberant, has never been still and has never wanted to lie down. She was walking at nine months, running at ten months, and bouncing on her first trampoline at 12 months. They could not be more different, but they understand each other perfectly.

000

He crawled out from under the Christmas tree - having secured it to its stand and then having spent a great deal of time adjusting it to the satisfaction of the womenfolk - and struggled to his feet only to be handed a great knotted tangle of fairy lights and instructed to "do something with this lot, please, dear."

Greg sat in John's armchair (as it was still known, even though John no longer lived at 221B Baker Street) to work on this new project and looked about at the activity in the comfortably familiar flat with a warm satisfaction in his chest. It had been, for the past six years, a tradition on the first weekend of December for as many of the family as was free to make Sherlock's flat festive for the season. * This was the first such time in years that had found them all free, and so the little family had decided to make a party of the event.

Youtubed Christmas carols played softly from Sherlock's confiscated laptop and a warm fire crackled in the fireplace as Molly and Mary wound garland around the room and put wreaths in the windows and over the mantelpiece. John and Mrs Hudson clattered in the kitchen, the doctor busy with brewing his special eggnog and the housekeeper with baking gingerbread. Ian had paper and crayons spread out on the coffee table, busy creating ornaments of his own design; his Irish setter, Gladstone, lay at his side like a great, feathery dust mop.

And Sherlock—who always treated this annual event with a resigned indulgence, but refused to chip and help as it would "encourage the madness"—was in his own armchair with Justine propped up in one arm. Just eight weeks old, the littlest Lestrade was gazing upwards in rapt attention, mesmerised by his voice as the consulting detective read to her from a medical journal. "Meissner's corpuscles, as a type of mechanoreceptor, are capable of detecting the lightest touch to the skin. . . ." he droned, and Justine reached up to grab at Sherlock's chin with both tiny hands as if to test this statement.

Sherlock had apparently decided that he was best qualified to guide the baby's early education, and Greg and Molly were actually quite grateful to him for the attention. While Greg's first daughter, Rose, had been a quiet and complacent infant and Ian Watson had been a studious and sombre one, Justine was a fussy and frequently unhappy little girl with a powerful set of lungs. Their paediatrician had assured them, as had John, that there was nothing wrong with her—that her nearly month-long stay in hospital, first because of her premature status followed by a fight with pneumonia, had no lingering consequences. She was a perfectly normal baby who happened to be miserable a good bit of the time. But they had a lot of help from their friends, who were always ready to step in and give the exhausted parents a break; and Sherlock had been especially willing, oddly enough, to spend time with Justine.

Greg worked out the tangles from the first string of fairy lights and handed it over to the girls, who began winding them through the branches of the fir tree, singing along to "Jingle Bell Rock" as they did so. Mrs Hudson handed him a full mug of eggnog and he took a grateful sip before tackling string number two. And then Justine began to wail as if her heart would break. Sherlock stopped reading and looked at her with a sigh. Greg began to rise.

"Let me," John said, handing the mug of eggnog he was carrying over to his wife and taking the baby from his friend. "She's had enough of corpuscles and receptors for one day." Sitting on the sofa, he held her upright with her little feet on his knees and began to bounce her up and down. They had all learned very quickly that Justine did not like to lie down—she wanted to be upright and, most of the time, to be moving about. She loved to bounce, and if she felt something solid under her feet would push herself up and down energetically.

"This is the way the ladies ride: tri tre, tri tre, tri tre," John crooned in his pleasant tenor, and Justine stopped her fussing and began to gurgle happily. Gladstone, curious about this new activity, rose and wandered over to watch, shoving his wet nose against John's hand. "This is the way the gentlemen ride: gallop-a-trot, gallop-a-trot. This is the way the farmers ride: hobbledy-hoy, hobbledy-hoy."

"A child's brain is hard-wired to learn language from birth," Sherlock sternly informed whoever would listen. "They devour vocabulary as birds devour crumbs. To feed her with nonsense words is to do a grave disservice to her development."

"Everyone needs a bit of nonsense in their lives, Sherlock. Don't we, Jussy? Yes, we do," John smiled, and Justine cooed back and did enthusiastic deep-knee bends, balanced on his thighs. "This child has very strong legs, you know that? She'll be walking early, I wager."

Ian had followed his dog, abandoning his colourful task in favour of a more appealing pastime. "It's not nonsense. It's omna. . .onma. . .motna. . ."

"Onomatopoeia. Well done, Ian," John supplied, proving that he also subscribed to the early development of a good vocabulary, nonsense words notwithstanding. Her game interrupted, Justine began to protest loudly and push harder with her little feet. John obediently began bouncing her again. "This is the way the ladies ride. . . ."

"That's a terribly sexist song, Captain. I'm quite ashamed," Mary scolded teasingly. "Don't you think so, Molly?'

"I do," Molly nodded somberly. "I can't believe you are teaching this to my daughter, John. The ladies can gallop-a-trot as well as any gentlemen, I'm sure."

"That's quite true; as well as, and better," John agreed gravely. "And they can also out-hobbledy-hoy the very best of farmers."

"Now that's rather classist, don't you think, John," Greg put his oar into the banter. "Why can't the farmers gallop-a-trot along with the gentlemen, is what I always ask myself."

"I believe it's more to do with the breed of horses they use than anything," John explained with a completely straight face. "I'm sure that if the farmers could get thoroughbreds to pull a plough they would all happily gallop-a-trot in their spare time. But can they tri-tre as well as the ladies can, I wonder?"

Sherlock was watching this exchange with an incredulous look. "You've all gone entirely mad," he concluded. "I believe I must sue for custody of your children before you've completely ruined their vulnerable minds."

Mary was shaking with laughter by this time. "So long as you bring them to visit us in Bedlam on weekends and holidays," she chuckled. Sherlock rolled his eyes and returned to his journal.

The last bit of wire untangled, Greg stood and began to string the fairy lights along the mantle and around the bookcases, listening to the music and to the cheerful giggling of John and Ian playing games with Justine. Sherlock and John had turned his life around in many ways over the years, Greg mused as he hummed along with a soulful rendition of 'O Holy Night'. Sherlock had quickly helped him to achieve the highest clear-up rate in the history of Scotland Yard and had slowly helped him to let go of his disaster of a marriage. A man could not live long in self-deceit with the genius detective as a consultant! But John had given him what he had been unable to find either on the job or in his private life: the friendship of an equal. Greg's counterparts and superiors at NSY were frequently jealous or resentful of him—or worse, intimidated by him. And although Greg enjoyed the respect of his subordinates, he could not confide in them or be entirely himself with them. But in John, he found a friend who understood Greg's job and the world they both lived in; a mate for whom there was no need to impress or to guide; a fellow soldier well-acquainted with their common battlefield. With both Sherlock and John, Greg could be entirely himself, strengths and weaknesses alike, without fear. It was a rare gift for which he was very grateful.

Now Justine had had enough of bouncing and was, though not quite crying, complaining about it in a whiny tone. John stood and began to walk about with her, to no good affect.

Mary turned from the tree, which she and Molly were festooning with bright, shining ornaments. "Oh, do stop pinching that baby, John Watson!" she teased. "Come on, Justine! You've had enough of the menfolk, haven't you?" she soothed and swept the baby into a graceless dance to the tune now playing on the laptop. Greg and John exchanged knowing looks, both smiling affectionately. Their Mary had no sense of rhythm whatever, but Justine did not seem to mind.

"The mood is right. The spirit's up. We're here tonight, and that's enough. Simply having a wonderful Christmas time!" she danced and sang, and Justine happily babbled along. Gladstone gave one excited bark and wove himself around and around Mary's feet as she danced, frequently tripping her up.

"Come here, Gladstone!" John ordered, and dog reluctantly slunk to sit by his chair at the fireside. "She's unbalanced enough without your help," John grinned, and Mary stuck her tongue out at him.

"I wanna dance, too!" Ian cried. "Me, too!"

"I'll dance with you, Little Bear." Molly put down the box of tinsel she was holding and picked him up, swaying about the room and singing along.

Greg could not stop a satisfied smile from gracing his face as he watched these two lovely women and these two precious children, four people whom he loved with all his life, dancing about a warm and homely room all draped with Christmas cheer. It was hard for him to grasp that such beauty existed in his world. His life had changed drastically since this time last year, and it was all due to them. Mary had charged into his life six years ago- his Rose come back to him again- and claimed him as a father, pulling him past the friendships he had already formed with Sherlock and John and into a strange little family. + And then she had dragged Molly into this family circle as well.

Greg had never particularly noticed Molly except as a brilliant and trustworthy pathologist whose help was often invaluable to his investigations. But his interest perked up when she and Mary began committing crimes together in order to solve a murder. ** And then, last Christmas, Ian quite innocently and naively nudged them into going on a date; the rest was history. ++ Here he was, one year later, with a wife who loved him and a child he would die for, happier than he ever thought he deserved to be. His thoughts began to circle along with the whirling dancers—if he hadn't met Sherlock, he'd never have met John; if he hadn't become friends with John, he'd never have met Mary; if he'd never met Mary, he'd never have learned to know Molly. And if not for Molly, there would be no Justine.

Mrs Hudson handed him a plate of biscuits and then seated herself on the sofa to sip her own eggnog. The mother to the lot of them, she smiled at the antics of the young people indulgently. She patted his arm. "Look at the little love," she murmured, nodding towards the dancers. Justine, he could see, had fallen asleep on Mary's shoulder.

"Here, let me take her, dear," Mrs Hudson said to Mary, who gratefully placed the now dead weight of the exhausted baby into the grandmotherly embrace. Greg seated himself beside her and was immediately climbed upon by an affectionate Ian, who helped himself to his Papa's gingerbread.

"She's a bit of a manic-depressive, our Justine, isn't she?" he remarked cheerfully. "Mood swings and all."

"She's a perfectly normal baby," Mrs Hudson admonished gently. "We all have our own little quirks, don't we?"

"She's not many-pressif," Ian objected. "Jussy's bored."

Molly, who had resumed bedecking the tree with bows, turned around. "Bored?"

Ian nodded earnestly. "She wants to run and jump and fings. But she can't, so she gets fuss . . . fuss-stated. She's bored wiff being a baby."

"A very sensible assessment, Ian," Sherlock commended the four-year-old. "I had come to the same conclusion myself, as I am very familiar with being bored and frustrated."

"Well, she won't be a baby for long, if you are any measure," Mary chuckled ruefully. "You've grown up far too quickly."

"Yes, she'll be running around and climbing the walls soon enough," John agreed. "And then won't we all be in trouble!"

Greg sat back, hugging his grandson to him comfortably, and surveyed his odd little family once again. When he had been raising his Rose, he had been completely on his own. He would not trade a moment of her life, but it had been lonely and difficult, and when she died his grief had been a private and secret thing. But Justine would have a whole loving family to dote upon her and to guide her; and Greg and Molly would never be alone, whatever happened.

This was, he realised, the very best Christmas he'd ever had.

000

Authors Note: If you also follow my main AU, this particular Christmas corresponds to the story "The Danger of Light and Joy." In this AU, Mary does not lose her baby and does not die and Molly never moves to Edinborough—therefore Molly and Greg marry a year earlier than in the main AU.

*This tradition began the year John and Mary married. See "A Watson When You Need One" Chapter 11.

+See "Family Dynamics" chapter 4

** See "Making Friends and Forming Alliances" chapter 3

++ See "A Watson When You Need One" chapters 22-23