Need you to go up to our room and look after Charlie now

- Today 5:18am

Sherlock stopped dead in the middle of the corridor, staring at the phone in his hand. His pulse had left all its usual spots, and was now located in his throat.

This was a text that John didn't want an answer to, of that Sherlock felt sure. At least, he didn't want any answer that wasn't:

Going right now. Give my love to Molly. - S

- Today 5:19am

Guilt pulled at Sherlock as he made his way toward the nearest staircase. Well, what exactly did Lestrade want from him? Was he supposed to help John and Molly, or keep out of the way and do nothing? Besides, Lestrade had vastly overestimated how high he actually was right now. The last of his stash had been weak, cheap street drugs acquired via the Homeless Network at the last second, and his high had dwindled into nothing almost immediately. At least, that's what it had felt like.

If everyone thought him competent enough to solve crimes while in this state, then surely he was capable of caring for a toddler. One who was probably asleep at this early hour, anyhow.

The second and third floors of Arndale Hall consisted, it seemed, of a series of interconnecting and almost identical corridors, but Sherlock had no trouble working his way back to John and Molly's assigned bedroom. He tapped on the door with two battered fingers, immediately hearing a surprised little rustle of bedclothes behind it.

"Jake?"

Sherlock conquered the urge to explain to Hayley the differences in the way a trained police officer and a graduate chemist knocked on a door. Instead, he simply said, "It's Sherlock. Can I come in?"

"Just a second."

Neither did he indulge in any speculation as to what Hayley had been expecting from a visit from Jake, instead waiting politely while she gathered herself into a fit state of dress to open the door. Judging from her puffy face and the hollows under her eyes, she'd either been asleep or trying to keep herself awake. More than likely the latter, even though Charlie, confined to a strange cot and without her parents and entertainments from home, had fallen asleep again. The little girl twitched as Sherlock shut the door behind himself, but did not wake.

"Hi," Hayley said, barely above a whisper. "What's going on?"

"I've come to look after Charlie."

She blinked. "You?"

"Yes, me," he said, annoyed. "I'd have thought you'd be more grateful for the break. John asked me to do it more than a month ago, though I think he planned for us to be at Baker Street at the time."

She looked at him as the penny dropped. "Oh, shit."

"That seems to be the prevailing opinion, yes." Then, in different tones, "Did you know, you do that exactly like your father?"

"Is there anything I can do to help?"

Sherlock was tempted to ask Hayley to stay with him. He had a vague notion, and he'd had it from the day John had asked him to babysit Charlie, that the process should be supervised by a female person. He remembered how much John had relied on Mrs. Hudson and Harry to help out with Charlie in her first six months, even though neither had bore a child herself and couldn't logically be expected to know any more about childcare than a childless man.

"No," he finally said, looking Hayley over carefully. "No, I think you're probably best employed in sleeping for the time being." He'd just observed something about her; something he hadn't expected. Something that then connected with another observation and crashed into a deduction that left him open-mouthed for a second.

Of course, it was possible, just, that he was wrong. But the more he considered it, the more perfectly obvious it seemed that…

"I'd feel a bit crap for sleeping when everyone else is running around like headless chickens," Hayley was saying, apparently oblivious. "I might go find Dad…"

"He's busy," Sherlock said. The last thing he wanted was for Hayley to immediately find her father and explain that he'd just relieved her of babysitting duty.

She raised one eyebrow. "Busy?"

"I meant 'ill'," he said, then followed up swiftly with, "Melissa and her mother are in my bedroom. Perhaps they'd like to see you."

"Perhaps." She yawned into one hand. "Okay. Thanks for getting me out of this, Sherlock. I don't know which is worse, her being boring when she's asleep or her being a little bit too interesting when she's awake."

"Oh, I'm sure you know my views on that," he said. Although he still had a habit of lamenting "boring" whenever the world around him seemed too tedious for words, he'd never expected infants to be entertaining. And the more passive Charlie was, the more he'd be able to sit and think about the Hayden murder.

Hayley had been sitting on the bed putting her shoes on, and stood up. Before she could leave, though, Sherlock gently touched her wrist. "Hayley…"

She stopped, looking confused; and he wondered if it was the first time he'd ever actually touched her.

"I'm so sorry," he faltered. "About-"

"Don't, Sherlock." She shook her head and, with her free hand, gently brushed him off. "Don't do your thing on me right now."

"Is there anything—"

"Yes," she said. "Yeah, there is. You can stop it with your deductions, and you can definitely keep your mouth shut about whatever you think you know. Thanks."

At twenty-five minutes past five, Greg finally emerged from the basement bathroom—he'd collected some interesting ideas for renovating his home bathroom on this trip, if nothing else. He made his way to the second-floor room Sherlock had offered to Melissa and tapped on the door. After a second or two, Liz answered, slipping past him into the corridor with a mouthed taking a break. He found Melissa on the bed rather than in the bathroom, which was an improvement on how they'd parted. He pulled a chair over as quietly as possible, assuming she was asleep, but as he sat down she stirred.

"Hey," he said. "How're you feeling?"

"Bloody awful," she mumbled, stretching her arms out like a cat.

"At least the only way from there is up," he said to her, mentally adding on for us, anyway, and brushing aside the thoughts of how Molly was faring. Nothing he could do about that except what he always did: be useful where he could be, stay out of the way where he couldn't be. "This, Mrs. Lestrade, is the extremely romantic first day of our married life together."

"Oh, Greg, you lug. You know I'm ridiculously happy, right?"

He blinked. "Really? In that case, I've never seen someone enjoy food poisoning so much."

"Well, maybe I'd be even happier without the food poisoning." She moved aside a little, patting the mattress next to her. Unable to think of a good reason why he shouldn't, he lay down beside her, shoes and all, head resting on her shoulder. She traced over his cheek with one finger.

"I just kind of left you here," he said. "Shouldn't have done that."

"You know I usually want to be left alone to sleep when I'm sick," she said. "And every time I wake up, I think, 'yeah, that's my husband—being awesome, off solving a crime.'"

"I'm not solving it fast enough," he admitted.

"Well, it's not like Elizabeth's on your case telling you to hurry it up," she said.

He frowned, reaching over to put his hand against her forehead.

"Deliriously happy, Greg." She wrapped her arms around his neck, and he noted with concern how hot and damp they felt on his skin. "How's Molly?" she asked at length.

Lestrade had received a text from John on his way up the stairs; a FYI, rather than a request for help. "About to have those twins, apparently," he said.

"Well, she's… wait, you mean about-about?" She made a movement as if she was trying to sit up. "I should go help," she said.

"No, you shouldn't," he said. "Lie down. The last thing they need is you in there, throwing up and passing out and spreading germs from one end of the room to the other. It's not like you're a wealth of experience in that department, anyway."

"Bastard," she mumbled, giving up for the time being and closing her eyes. "But seriously, is someone giving them a hand?"

"Yeah, of course," he said automatically. But on thinking about it, he hadn't the faintest idea who. All he hoped was that Sherlock would stay out of the way long enough to come down, before John noticed at the worst possible time.

No sooner had the door closed behind Hayley, and Sherlock had taken a deep breath—definitely coming down, more sober than not, he decided—than Charlie stirred in her crib, rolling over and pulling herself into a sitting position. Her ash-blonde curls fluffed around her head like a halo. But Sherlock knew Charlotte Watson well enough by now to realise those curls were, if anything, hiding devil's horns; and he loved her all the better for it.

"Mummy," she said sleepily, rubbing her eyes with her chubby fists.

"Not quite," he replied. After the Watson's had moved into the flat downstairs, he'd read up as much as possible on child development, expecting it would come in handy at some point. One conclusion he'd come to was that it stunted a child's communication skills to be constantly addressed with baby talk. "I'm sorry to be the one to tell you this, Charlotte, but your mother's quite indisposed at the moment."

Although Charlie hadn't the faintest clue what the word 'indisposed' meant, she'd just woken expecting to be comforted by one of her parents and found herself in a strange bedroom with Uncle Sherlock instead. Her bottom lip wobbled, then dropped, and she burst into tears. "Mum-MEEEEE!"

Oh, my God, Sherlock thought. What do I do…?

He wrinkled his nose as the first thing he needed to do with Charlie quickly became obvious. Well, he conceded, lifting her out of her cradle and looking around for where Molly had put her bag of nappies and other baby-related paraphernalia. At least this was a practical endeavour. Even John managed to change nappies several times a day. This Sherlock Holmes could do, with an underlying little satisfaction that he was doing exactly as John asked him.

John was staring out the window again, though there wasn't anything out there he hadn't seen before: darkness and a flurry of snow that occasionally thudded against the pane. It did seem to be dwindling, though, or perhaps that was just wishful thinking. Behind him, Molly was on her feet and clinging unsteadily to the back of one of the armchairs.

"It's okay, Lolly," he said, going to her side and fanning her face with some copies of the witness statements Greg had insisted everybody write down earlier. "It's fine. Everything's fine."

It was times like this he was so glad he'd spent six years studying medicine, he thought: so he could keep repeating it's fine, everything's fine at his wife while she was suffering, and otherwise be of no medical use to her at all. He'd almost have preferred Molly to have a broken arm. At least he could help with that kind of thing.

"I know it's fine," was all Molly said. She grabbed at a nearby towel and heaved sharply into it, though he could tell nothing had come up, judging from the way she then used it to wipe sweat off her temples once she'd come up for air again.

"Anyway," he said, trying to stay cheerful. "Charlie took ages to be born; what, nine hours..?"

"Twenty."

His eyebrows shot up. "Twenty?"

"Remember, I went to the hospital the night before… they sent me home…"

"Well, twenty's even better," he said.

She gave him a Look, and he backtracked in confusion. That had definitely not come out the way he'd intended. "I mean," he said, "that's plenty of time to get to a hospital. If the storm dies down like Mycroft said it will, you'll be in St. Jimmy's in Leeds around nine o'clock. Maybe a bit past." He glanced at his watch. Quarter to six, give or take a minute or two.

"What if Mycroft's wrong?"

He looked at her as if she'd asked him what would happen if the sun froze over. "He's Mycroft Holmes," he said. "I've never known him to be wrong about anything… Molly-"

"Oh, God," she got out, fingers clawing into the back of the armchair. "Please, talk to me… keep talking to me, okay…"

"Just try to relax, it's going to be-"

"About literally anything else but this, John!"

"Okay, all right…" John picked up the papers to fan her face again, turning them over at the last second for a source of conversation that wasn't the impending premature birth of his children. "Okay," he said again. "So Donovan's just busted the alibi the Hayden brothers and Ishani Parikh gave, she says they weren't playing poker; Alec and Ishani were having sex in her room on the third floor, and Stewart can't explain where he was, and he keeps changing his story..."

"Maybe he did it..."

"Yeah, but how could he, when everyone could see he was in the doorway when it was broken open? So let's think this one out then: There was nobody in the Hayden's room when Greg came in, except Elizabeth and the people he'd seen ahead of him that he mentions here in the statement: Maureen, Stewart, Alec, and that Allison Marr woman."

Privately, John had already put Allison Marr on his list of suspects, even though everybody else seemed to regard her as being above suspicion. To him, this was exactly a reason to still suspect her. If Sherlock had been around to hear his thoughts on the subject, he'd have told him he'd watched too many TV crime dramas.

"Maybe he's… got an identical twin," Molly suggested, clawing at the back of the sofa again and taking a deep, shuddering breath.

"Molly-"

"Keep talking…"

"So," John went on, a little feverishly. "So, well, he might have a twin, but why would Stewart's secret identical twin that nobody knows about want to kill Elizabeth Hayden on her wedding night?"

"For God's sake, John, I don't know…"

John decided not to point out that he was only doing what she'd asked him to. "Um," he said, trying to look back down at the papers in his hand. "So the way I see it is, there's three options. Either the killer had already left the locked room when everyone arrived in it. Or the killer hadn't left the locked room and was still there when Greg and everyone else arrived, and left afterwards. Or the killer's invisible."

"That's still option two," she reminded him crabbily, dropping her shoulders and beginning to exhale deeply. "And you left out… suicide, a projectile, a pursuit, the body being dumped…"

"Are you gunning for any of those?" he asked her.

Molly shook her head. "No," she said. "Nowhere to fire a projectile from. Nowhere for a dying woman to hide a weapon. No blood trail to indicate she was chased into the room. She was killed where she lay and stabbed from the front…" She swiped at her face with the towel again and dry-retched into it.

"So she was facing whoever did it," he said, valiantly trying to ignore this.

"Mmm." Molly nodded, folded the towel and pressed it to her face again. "And not struggling. Not for the first stab, anyhow. Someone came to talk to her…"

Sherlock had found some milk biscuits in Charlie's case, given her one and taken another for himself, to toast the fact that they'd both just survived The Adventure of the Dirty Nappy without either of them crying or spreading the mess from one end of the room to the other. Charlie had by now accepted that she was on this adventure with Uncle Sherlock and refused to be put down, so he was pacing around the bedroom with her in his arms, jiggling her occasionally when she became too restless or heavy. "Enlighten me," he said. "At what age can I expect you to stop defecating in your clothing?"

Charlie, sucking enthusiastically on her biscuit, made no reply. With her slung low over his hip, Sherlock's arms were getting tired. Reasoning that the bed was a safe enough place for her, he put her down on it. Immediately, she dropped her biscuit on the mattress and reached back up for him with both arms.

"No," she wailed. "No, Sherwee!"

… Sherwee?

Oh, no. That was never going to do. Growing up with the name Sherlock Holmes had guaranteed him years of school bullying, even among schoolmates with names like Orlando Montgomery Talbot and Alasdair Wainthorpe the Third, Lord Dalhurst. But, though he'd not been consulted before it had been given, his name was Sherlock Holmes and nothing else, and not even infancy was an excuse for that kind of twee mangling of a perfectly respectable name.

"Okay." He scooped her up, sitting down on the bed with her on his knees, facing him. "Settle in, Charlie, and concentrate. We're going to play a game. Do as I do: Sher-lock," he said, overenunciating the syllables and pointing to his chest.

Charlie, confusion in her big brown eyes, pointed to her own chest.

"No; almost, but not quite." He gently pulled her hand toward him and rested her sticky fingers on his shirt. "Sherlock. I'm Sherlock. Can you say Sher-lock?"

"Sherwee!" she giggled, clapping.

"No," Sherlock said, shifting her weight on his knee. Part of her biscuit was in danger of falling onto his lap with a mushy thud, and for a second he had an impulse to break off the soggy part and put it in his own mouth, as he'd seen John do to spare the carpet or his jeans. The odd thing, though, was that he'd always thought it disgusting when John did it. "We're not having any cute nicknames between us anymore, Charlotte Mary Watson," he said. "Sher-lock."

"Sherwee," she said stubbornly.

Despite knowing full well that, at seventeen months, Charlie wasn't old enough to be doing this to annoy him, Sherlock still had to wonder for a second. This was exactly the way Molly got her own way in a conflict, and John had started to copy her. Just say the same thing over and over again until the person you're debating with gives up.

"Sherlock," he persisted; noting, with something that strongly resembled affection, that Charlie and John pulled the same faces when they were deep in thought.

"Sher…" she fumbled. "Sher…"

He waited.

"Sher…wee...?"

"Oh, for God's sake." Sherlock put his head in his hands and lowered it—a little too dramatically, as he found out when his forehead came into sharp contact with Charlie's.

He gasped and cradled the back of her head; exactly, if John or Molly had been on hand to tell him, the wrong reaction. "Oh, God," he said aloud. "I'm sorry, I didn't mean it, I-"

Initially, the unexpected Glasgow kiss had merely made Charlie alarmed. At this, though, she immediately melted into more tears.

"No-no-no," Sherlock begged, checking the bump on her forehead—virtually non-existent—and standing up, walking around the room with her, giving her a few energetic bounces. "No, stop; please, stop. I'm sorry. I'll make it up to you. What do you want? Do you want a…"

His mind filtered through the various options at supersonic speed. Drink? She'd just had one. Biscuit? Likewise. Toy? What if she demanded one that was sitting back at the Baker Street flat…?

"…Song?" he heard himself finish.

Charlie stopped, as abruptly as if he'd turned her tears off with a switch, and Sherlock inwardly groaned. Molly occasionally sang for Charlie, so she knew the word 'song' and she wanted one, apparently on the spot. Sherlock wasn't afraid of his vocal skills being judged by someone who wasn't even toilet trained yet, but the immediate problem was that he couldn't think of a single thing that was appropriate. There was a nursery rhyme about a spider that Charlie liked, he knew; but just at that moment, he couldn't recall a word of it and only had a vague idea of the tune.

"Song?" Charlie prompted him. "Sherwee song?"

Well, on consideration, there was one that he'd liked as a child. He had no recollection of who had taught it to him; no memory of his mother ever singing anything at all, and Mycroft was hardly going to indulge his baby brother in sentimental nonsense. Sherlock wouldn't normally have lowered himself either, but with Charlie now insisting "Song! Song!" and liable to start screaming if one didn't begin soon, he hitched her up on his hip again, trying to remember the words:

O, there was a lofty ship and she sailed upon the sea,

And the name of that ship it was the Golden Vanity

And she feared she would be taken by the Turkish enemy

As she sailed upon the lowland, lowland low

She sailed upon the lowland sea.

Then up stepped the cabin boy, just the age of twelve and three…

A/N: Thanks again for reading. The ballad Sherlock sings to Charlie is called 'The Sweet Trinity' or 'The Golden Vanity'. It's one of the Child Ballads, traditional, and so the lyrics are completely in the public domain. It's a sordid little song about war, piracy, terrorism, murder and implied incest. I think child!Sherlock would have liked it. There's a particularly good version on Youtube by a trio called Three Together.