"Yes, yes, you've said." Sherlock shifted the baby from his shoulder to his hip. She wasn't heavy, not even at eight months, but she was squirmy, and liked to pull on his hair. "Bath, bottle at seven, then bed. We know. Don't we, Alice?" He tried to turn her out a bit in case she wanted to wave goodbye to her parents but she just laughed her baby laugh and flung her head into his armpit.

"Come on, John. They'll be fine." Mary tugged at John's arm and tried to pull him toward the door. Previous observation of couples had indicated to Sherlock that the mother tended to be the parent who found it more difficult to separate from the child; leave it to the Watsons to reverse that trend.

John leaned in to give Alice a kiss on the cheek and then Mary did the same, adding a quick hug that enveloped Sherlock as well. "Be good," she whispered; Sherlock was fairly certain she was not talking to the baby.

"Oh, we'll be good," Sherlock said, and shut the door behind them. "Won't we?" He lifted Alice to speak to her face, and then wondered at himself. He thought he would only talk to her as if she might answer when there were other people around—Mary and Mrs. Hudson in particular both seemed to find it endearing—but apparently he was continuing the practice now that they were alone. He shrugged; might as well go with it.

"So, Alice, what do you want to do first?" He held her fast against his hip and twirled once around the sitting room. She giggled and the next thing he knew they'd been spinning for ten minutes, interrupted only by the occasional bout of swooping, necessary whenever Sherlock felt himself grow too dizzy.

"Enough." He dropped down onto the sofa and let her bounce softly in his lap. Everything made her giggle, really; it wasn't much of a challenge. So, ten more minutes of laughter, caused simply by funny faces and a few rounds of peek-a-boo. Peek-a-boo. Really. How cliché. At least no one else was there to see.

Eventually Alice tired of the game and started trying to crawl off the sofa. "Hang on, darling. That floor is hard." He lifted her down.

She attempted to stand by gripping his leg but slid down into a pile of tangled baby limbs instead. She straightened herself out quickly enough, then crawled away from the sofa.

Sherlock scrambled to shove the coffee table out of her path, but she only made it about a foot away from him before she abruptly reversed and returned to the sofa. She pulled herself up to sitting using his trousers, but getting her feet under her was still a bit too much.

"I'm sorry, my sweet. I'm afraid standing up by yourself is still a couple of months off." He hoisted her up by her armpits and then that became a new game. Up, down, crawl away, not too far, crawl back, and it was all very, very amusing. For Alice, at least. For his part Sherlock entertained himself by trying to determine if she favored her right or left hand, but she switched between them continuously, sometime reaching for him with her left and sometimes with her right, and never putting the same hand forward first when she crawled. "Well, your mum uses her left hand for most things, including shooting people—trust me on that—but your dad shoots people with his right hand and does everything else with his left, so I understand why you might be confused."

He could see how some might be bored by the repetition of an infant, but Sherlock found Alice quite fascinating. A tiny little John and Mary clone, complete with their stubbornness and unending ability to surprise him, plus she didn't object when he rubbed his face against her fuzzy blond hair. Which smelled like rice cereal and pureed peaches at the moment. Maybe it was bath time already.

When they got to the bathroom Sherlock set Alice on the little rug in front of the toilet before shedding his suit jacket and rolling up his shirtsleeves. Undressing a baby was easier than he expected; all he had to do was pop all the snaps and then tug on her clothes and she willingly rolled right out of them, leaving him facing his first solo nappy change. He squared his shoulders and settled back on his knees and pulled open the sticky tabs.

"Oh, when did you do that, now, hmm?" He hadn't smelled anything, although now that the nappy was open there was a bit of an odor. He balled up the nappy and wiped her bottom off, even though she seemed fairly clean, given the circumstances. Honestly, given the small amount of fecal matter she apparently produced, why all the fuss about dirty nappies? Maybe most parents and caretakers were just more squeamish than he was.

The bath was even easier than the nappy change: not too much water, not too hot, make sure not to let go of her even though she could sit up well on her own. He didn't think there was any real danger of an accidental drowning—he might be easily distracted under some circumstances, but he was responsible when he needed to be—but he also didn't fancy having her lunge forward unexpectedly and end up with a faucet-shaped bruise on her head. Even John would notice something like that, to say nothing of Mary.

He thought that children were supposed to cry when getting their hair washed, but he used his hand to shield her eyes while he rinsed and Alice didn't even seem to notice. No More Tears, indeed. Her hair was still so thin and short that the whole process took less than a minute. He fluffed up the already-drying wisps with a dry flannel and tried not to be jealous.

The rest of the bath was less washing up and more gentle splashing at each other; he'd already wiped her bum and she was sitting in water so all he did was dampen the flannel and run it over her chest and arms, then let her chew on it for a while. Gnawing the flannel followed by slapping it against the water seemed to be her preferred technique; when he judged that he and the floor around him were sufficiently wet, bath time was over. Maybe the Watsons had a deeper tub.

He dried her off quickly so he could get the nappy on; Mary had coached him through it the last time they'd visited, and stressed the importance of timing. Again, not a difficult process: something anyone over the age of seven should be able to do. He was certain Mycroft had changed his fair share of nappies when Sherlock was Alice's age, though the thought made him shudder. Center the nappy beneath her, pull it up through her legs, hold her still with one hand while the other fixed the tabs in place, make sure the edges of the nappy weren't folded under the elastic around her legs, to minimize leaking. Maybe he would mention cloth nappies to Mary again. John tended not to appreciate parenting advice, but Mary might be amenable, and after reading extensively, Sherlock was certain cloth was the way to go; the increased use of water and laundry soap for washing was much less disruptive than the manufacturing of the disposables, not to mention the landfill contributions. Yes, he would definitely have a word with Mary.

Nappy secured, he rummaged in the giant changing bag for Alice's pyjamas. The bag was fairly fashionable, definitely to Mary's taste, but the same could not be said for the poor child's clothing selections. Two choices for sleepwear: a pink polka dot one-piece with a zip—the polka dots were giant, and so very pink—or a two-piece number covered with—were those hippos? Unisex, at least: no need to stereotype a child at such a young age. Bravo, Mary and John, but hippos were neither green nor yellow, nor did they tend to smile or stand on two feet. He went with the pink because it seemed it would be easier to wrangle Alice into the single piece; he'd had to let go of her to find the pyjamas and she was now happily crawling around the tiny floor of the loo. He hoped Mrs. Hudson had cleaned it recently.

As it turned out, putting an excited eight-month-old into a one-piece sleepsuit was not as simple as it sounded. He thought the single long zip would help; once her legs were in he could zip it halfway and then work on the arms, but she preferred kicking outside of the clothing to putting her foot down into the leg. And the suit was footed, so he couldn't reach up and grab her toes to pull her leg through. He did get her into it eventually, mainly by virtue of the fact that he was over ten times her size and possessed of more patience than most people gave him credit for.

Alice apparently didn't agree with Sherlock's fashion selection. For the first time that evening, she began to fuss, squirming and kicking and starting to cry. He checked to make sure the zip wasn't pinching or the fabric chafing; as far as he knew, she wasn't generally sensitive to the texture of clothes. Maybe she was just hungry; it was nearly seven.

"All right, come on, then." He unfolded himself from the floor and lifted her up. "Let's get you fed and happy again so I can tell Mum and Dad what a perfect delight you were the entire evening."

He set her in the travel cot that was to serve as her bed so he could have both hands free to prepare her bottle. She did not approve. Loudly. Luckily, Mrs. Hudson was not home to hear, or she would've come upstairs to cast aspersions on Sherlock's babysitting skills.

It took only a few moments to warm the bottle in the device Mary had provided—she'd advised him that it only needed to be room temperature—and then he returned to the sitting room and the screaming baby, smiling his best baby-cheering smile; usually the mere sight of Sherlock made Alice grin.

As soon as he stepped out of the kitchen he realized what the problem was, if not quite the full extent of it. She was still wailing, but based on the scent that was permeating the flat she should've now felt much, much better.

Sherlock returned the lukewarm bottle to the kitchen and rolled up his sleeves again. Back to the loo, which seemed the most obvious place for a change, although earlier Mary had changed her on his bed. No. Not with that stench.

For a moment he despaired at the thought of having to wrestle her back into the sleeper again, but then he unzipped the outfit and saw what had happened to it. So that was why Mary had packed two, not just to give him more sartorial choices.

He used the irredeemably dirtied sleepsuit as a barrier to protect the rug of the loo while he cleaned Alice up using numerous wet wipes. Maybe he could see the sense of the disposable lifestyle; at least he didn't need to rinse out the nappy. He could just ball it up with the wipes inside and toss the whole package in the bin. And then take the bin bag out, tie it tightly, and toss it in the hall in hopes of reducing the smell. Either that worked somewhat, or his poor nostrils had decided to concede defeat and cease functioning.

He pulled out a fresh nappy along with the second pair of pyjamas and then realized when he stripped off the first pair that she had somehow managed to dirty herself all the way up her back. Was she ill? The soiled nappy from before the bath had featured nothing remotely like this. She wasn't acting ill; once he'd gotten her bottom bare she'd gone back to her usual joyful self, gurgling and stuttering a few vowel sounds over and over at him. Possibly he was now named woowoo.

Sherlock sighed and turned on the taps on the tub again. The second bath was much quicker; he didn't let her chew on the flannel this time.

When she was clean and dressed once more, Sherlock returned Alice to the travel cot; this time she didn't protest when he left her to retrieve her bottle.

The milk was still at room temperature, obviously, since it had been sitting on the kitchen table, although just to be safe, Sherlock tested it himself. He shook a few drops out onto his finger and then licked them off. Yes, room temperature, though it tasted not at all like what he expected. Very sweet and not too creamy; he wondered how much the taste varied from day-to-day, if it depended on Mary's diet. Would it be different later tonight? She and John had planned on Indian food before the cinema; that would certainly change the flavor, would it not? Maybe she would let him experiment? John would—well, John would either laugh or punch him at the suggestion; it was one of those things that was impossible to predict. Mary might let him, though, especially if he could then give her data about how various foods impacted Alice's digestion and behavior. Something to think about.

Regardless of taste, Alice accepted the bottle eagerly. She seemed a bit put out when she discovered she couldn't reach high enough to pull Sherlock's hair with one hand while also burrowing into the crook of his arm and drinking from the bottle, but then she found his free hand and wrapped her tiny fingers around his thumb and snorted with pleasure. He wriggled them both around until her head was just below his chin and her thin tufts of hair tickled his nose. Now she smelled of baby shampoo, a familiar, soothing scent, even though he was sure he could not recall what his own hair had smelled like when he was a child.

He let the pleasant haze of feeding her surround them both, half-keeping an eye on the level of milk in the bottle but mostly just enjoying the comfortable weight of her in his arms. She drank almost the entire bottle with barely a pause. When there was only a centimeter or so left she let the nipple slip out of her mouth and then followed it with a loud, contented burp.

Sherlock tipped the bottle away and considered her. "Got any more of those?" She swatted at his chest and he turned her around to pat gently at her back. He thought she was a few months past the spitting up stage, but he wasn't willing to sacrifice his shirt to test that theory. She didn't burp again, and when he tried to give her the rest of the bottle she refused. Feeding time was done, which left only bed.

He checked the nappy one final time, but it was still dry and clean. John had told him he could just put her down in the travel cot without any fanfare; Mary had recommended singing a song to her first. They both agreed that she would sleep without much fuss, given that this was her usual bed time. They were definitely both the type to have established parenting routines; Sherlock thought he himself would probably fail miserably as a parent simply by virtue of being completely unwilling and unable to follow the same schedule every day.

The moment her bottom hit the cot Alice started to cry. Not the loud, uncomfortable wailing of earlier—he sniffed, but it was definitely not another nappy issue. This was more a pitiful sniffling cry. She needed a song, then. He immediately realized that he knew very few songs with words, and none of them were particularly soothing or appropriate for children. Oh, the Happy Birthday song; that was one he'd never been able to delete. He sang it through twice, slowing it down enough that she would mistake it for a lullaby, were she old enough to know the difference. She did quiet down while he was singing, though it certainly didn't seem to make her any more inclined to sleep. "It helps if you lie down," Sherlock told her, and gently guided her down onto the cot's mattress. She popped back up to sitting as soon as he withdrew his hand.

Sherlock raised his eyebrows and shrugged. "Suit yourself. I've seen your father fall asleep sitting up, so I know it's possible." He stepped away from the cot and she started to whimper again. The whimper turned into a more full-throated cry once he was out of sight, as he stepped into the kitchen to rinse out the empty bottle.

Sherlock walked back out into her line of sight. "You've slept here before, remember?" Probably no, she didn't remember. She was eight months old. Or maybe she only liked to sleep in the travel cot during the day, as she had several Saturdays ago when John brought her by while Mary went out to the shops. Or maybe she did remember that, and now she wanted Dad or Mum around before she would sleep here again. Or maybe she now associated the flat and Sherlock himself with fun playtimes, not with sleep; yes, that was probably it. He smiled and lifted her out of the cot. John and Mary would be at least another hour; maybe she could stay up a bit longer.

But when he sat down with her on the rug for another round of crawling and peek-a-boo, she didn't respond as before; instead she wormed her way onto his lap and let her head flop back against his chest. "I knew you were tired," Sherlock murmured. "Mum and Dad have you trained quite well."

Back in the cot, but this time she didn't even let him get out of her sight before starting the sad baby crying again. His gaze brushed over his violin, standing sentinel in the corner; he might be able to lull her to sleep that way, although honestly he was worn out enough himself that the idea seemed a bit too complex. Instead he hefted Alice out of the cot once more and lay down on the sofa with her atop his chest. She pushed herself up on shaky arms to stare at his face for a moment, then collapsed onto her stomach, head turned to face the back of the sofa. She sighed against the fabric of his shirt and brought her hand up to her face to gnaw on her own knuckles. Interesting self-soothing technique; thumb-sucking would doubtless be less irritating but more commonplace. He was sure she would never be an average child, thankfully.

Sherlock wrapped his hands around Alice's tiny body, feeling her breathing slow to a steady, reassuring pace. He closed his own eyes, just for a moment. He was right; this babysitting lark wasn't too difficult. Maybe he would even offer to do it again sometime.