If you were to ask John Watson to use the words Sherlock Holmes and kids in the same sentence he would probably frown slightly before providing you with a sentence featuring not only those words but also the words mine and field.

Sherlock Holmes and kids equals minefield.

John knew that the Mollies of this world wanted Sherlock to be unexpectedly and completely marvellous with children. Mollies were a category of people that, in John's head were besotted with Sherlock Holmes, who despite harsh words and arrogant dismissal still remained starry eyed. John was occasionally a Molly himself. And if Sherlock did not actually have hidden parenting skills and child care depths then Mollies really wanted children to be unexpectedly marvellous with Sherlock. In either case a meeting between a child and Sherlock should ultimately be life-affirming in an amusing and unexpected way.

In reality Sherlock was just himself with children and talked to them the same way he talked to adults; with an air of superiority and as if they were idiots. Of course talking to children as if they were adults was a tactic that was either absolutely perfect or absolutely terrible. Children loved being treated like adults. But on the other hand they generally didn't bounce back well from insults about their parents or their pet rabbits. Their dead parents. Their dead rabbits.

So John approached any situation involving a child and Sherlock Holmes with more than a little trepidation.

One dreary Tuesday afternoon, Sherlock was called in to consult on a case; supposedly a clear-cut suicide but Lestrade had his suspicions. Just got a funny feeling about this one Sherlock. I don't understand why she didn't leave a note. All those family photos in her flat. Something strange. John and Sherlock, there was no interpreter booked today which was making Sherlock antsy, even though he would never admit it were at the crime scene, a high rise tower block out in east London. They were stood outside in the quadrangle that sat in the middle of the three tower blocks, and the car park that made up the four sides of the estate, the wind half-heartedly whipping around them, a dampness in the air promising a rain storm that hadn't materialised, yet. Earlier Lestrade had walked them through the dead woman's flat where Sherlock had peered carefully at every photo, his nose pressed up to the glass. Then, outside in the quadrangle Lestrade had gone over the remaining details and Sherlock had watched Lestrade with that strange intensity he had before abruptly turning and wandering off across the estate.

'Got any ideas then? Sherlock!' Lestrade had half-heartedly shouted at Sherlock's back.

John and Lestrade had stood for a bit, watching as Sherlock busily mapped out the edges of the quadrangle – pacing the grass, before wandering over to the small playground that sat in one corner – John and Lestrade watched as he pushed at one of the swings – sending it into motion. Lestrade raised an eyebrow at John who shrugged. Lestrade started to mutter about coffee and sandwiches when John noticed a woman and a small boy approaching them. One of the boy's hands was held tightly by the woman.

'Hi. Excuse me?' She said as she approached them. 'Police right?'

Lestrade straightened up at that, smoothing down his tie and greeted the woman, who visibly relaxed after Lestrade showed her his badge and gave his job title.

The boy was blonde with dark brown eyes which squinted up at Lestrade and John as the adults spoke.

'You're investigating Catherine?' The woman had said to which Lestrade nodded. 'I spoke to one of your officers earlier, but then, well, this is my son Luke.'

'Hi Luke.' Lestrade directed down at Luke.

But Luke now only had eyes for Sherlock who was currently sat hunched over on a swing, with his coat up around his ears like some kind of overgrown scrawny bat. Luke's Mum was explaining that they knew the murder victim, Cathy and that they lived in the tower block opposite hers. Luke was tugging at his Mum's hand edging towards the playground.

'Is he with you?' Asked his Mum indicating Sherlock with a nod of her head. 'Is it alright, is he working right now?' At their reassurances she let go of Luke's hand and nudged him towards the playground with the touch of one hand to his shoulder. As Luke shot across the grass, she turned to Lestrade and John 'I hope your colleague is good with kids. He's about to get the full-on Luke experience.'

John smiled and hoped Luke was prepared for the full on Sherlock experience.

Bren, Luke's Mum wrapped her cardigan around her, hugging her arms against her body. 'He saw your friend out of our living room window. And then suddenly he was going nine to the dozen about the deaf detective.'

Lestrade and John exchanged surprised glances.

'He is Deaf isn't he?' Bren asked in mild alarm. At their nods she breathed. 'Luke saw him out of the window, I guess he'd seen him with the uniformed officers, and then said he'd seen him counting on his hands.'

She held up her right hand to demonstrate, her hand twisting through the number signs. John recognised how Sherlock would pace sometimes counting out something on his hands.

'Clever kid.' Said Lestrade. Bren smiled. And they all looked towards the playground – where Luke was now stood in front of Sherlock's swing – one hand pushing back his hair to proudly display a red hearing aid to Sherlock.

Sherlock's eye lit up in recognition and he lifted his hands up You sign?

Luke bounced on his toes. Nodding. Yes. Yes. Yes!

John honestly wasn't sure who looked more delighted. Sherlock jumped up from the swing, and grabbed Luke under the arms and deftly swung him up onto the swing. Luke shrieked in delight and grabbed hold of the steel link chains that held the swing seat to the frame above. To John's surprise Sherlock sat cross legged on the floor opposite Luke resting his elbows on his knees. John presumed (it was hard to tell from this distance) that he wore his tell me everything face.

First things first Luke removed his hearing aid and held it out in one hand for Sherlock to inspect.

'It's a new hearing aid. It's red which makes it totally cool.' Explained Bren shaking her head fondly.

Second things second Luke put back in his hearing aid, and asked if Sherlock had one.

Sherlock shook his head. But then seemed to think better and indicated home. No….well yes but it's at home.

Luke launched into a long monologue of signs – pointing up at his flat and across at Cathy's. Sherlock nodded along carefully.

Meanwhile Bren explained what she knew.

'Said it wasn't anyone he recognised, but that they looked nervous maybe like they didn't want someone to see them going in Cathy' flat.'

'Ok that's really useful. Great in fact.' Says Lestrade, scribbling some notes down in his notepad. ' I'm going to get an officer to come over and speak to you both about this more, get a full description, is that ok?'

Bren shrugs 'Anything to help. Cathy was a good person.' They all wander over towards the playground.

Luke had by now finished his story, John had watched as Sherlock asked a few questions and Luke replied. But soon Sherlock is just signing as Luke watches. At one point Sherlock had leapt to his feet and as he continued to sign, he pulled Luke's swing forward and then let him go, the seat sailing backwards through air, Luke shrieking as he flies back and then towards Sherlock. In between each push Sherlock carried on signing at Luke. This game lasted for only a minute or so and then Sherlock paced around the playground - but never turning his back on Luke. Luke didn't seem upset, instead jumping off the swing mid arc, landing in a way that made John's knees ache. As John, Lestrade and Bren headed towards them, Luke was following Sherlock around, his face rapt with attention, walking backwards, ducking, as Sherlock weaved his way around the playground.

'Are you getting this?'John asks Lestrade as they reach the edge of the playground.

'No not really. He's gone into supersonic speed.'

Bren frowned at the scene 'I don't understand why he's telling him what he had for lunch.'

'Mum! Mum!' Luke shouted as his right hand patted against the side of his head. 'This is Sherlock.' He turned towards Sherlock as he finished fingerspelling his name and Sherlock nodded. Luke beamed. Then Luke made a strange, to John's eyes at least movement around his neck, he seemed to pinch the air on either side of his neck just above his shoulders and made a flicking movement upwards. Sherlock reddened at this just as Bren said 'Luke.' Her tone half warning admonishment and half exasperated fondness.

Luke just grinned up at Sherlock and then spun back towards his Mum.

'I'm watching you.' Bren swung two pointed fingers from her eye towards Luke.

Luke bounced on his toes as he signed rapidly at his Mum, eyes wide twisting to look at Sherlock and then back at his Mum who watched him slightly bemusedly.

'Ah.' Said Lestrade.

'Bit not good?' Asked John.

'Bit not good.' Confirmed Lestrade. 'Sherlock told him about the skull. And that you had a Mars Bar, a Whispa and an Iron-Bru for lunch.'

It was John's turn to redden and he gave Lestrade a sideways look. 'Well yes. You would too if you lived with him.'

Bren chuckled and shook her head at Luke. Luke's eyes widened and he spun towards John, as he saw the blank look crossing John's face at his signing, he switched to English.

'Tell her.' His voice was round and soft like Sherlock's but higher pitched. 'Tell her about Mars Bars and Whispa!'

John reddened further and coughed. 'It's true I did.' He remembered the sign for true at the last moment and Luke's eyes lit up in triumphant.

Bren laughed. 'God it'll be what he wants for lunch every day from now on!'

And you, Bren signed to Sherlock. Do you have a skull?

Sherlock looked at Bren, down at Luke and across at John. His brow creased and John has a moment of startling clarity as he realised exactly what Sherlock is thinking, Sherlock was not sure what the right thing to do it is.

'Yes…' Said Sherlock's voice and he nodded once sharply.

Lestrade started slightly at that. Luke whirled around to his Mum his triumphant complete. I told you. I told you he signed gleefully. Bren shared a knowing look with Sherlock (Kids hey!) and Sherlock frowned and then offered a vague smile. John had a sudden urge to hug him.

Sherlock rubbed a fist against his chest. Sorry. He shook his head Can't lie. The tip of one finger touched his nose and then swung out.

Bren's smile widened. And Sherlock scrunched his nose slightly. .

'It's fine. It's good to meet a Deaf adult. Good role model for him a Deaf police officer.'

Lestrade and John both kept wisely silent.

Sherlock nodded at her and then turned to Luke. Keep using your eyes. And then wandered back over to the playground. Luke waved goodbye enthusiastically – slightly crestfallen that he had to make the sign to Sherlock's back. John sympathised.

Bren turned to Luke. Home she signed. John always forgot that that sign didin't specifically mean 221b Baker Street. Lestrade shook her hand and passed over his card. As she walked off Luke hung back slightly, and then turned to Lestrade and John. His face was serious as if he has some great secret to impart, and he beckoned them both closer, and whispered to them both eyes wide, hand movement slowly but with emphasis 'He showed me the sign for murderer.'

'Best not tell your Mum that.' Said John in alarm as Lestrade quickly made shushing movements with his hands. Luke nodded sagely, then dashed off heading first in the opposite direction to his Mum so that he could loop around in front of Sherlock.

'Bye Sherlock!' He yelled, hands waving. Then he dashed off after his Mum who was waiting at the door to the block of flats.

Later Sherlock, Lestrade and John were walking back towards the main road.

'Did you tell a small child the sign for murderer?' John managed to sign the whole question apart from having to fingerspell murderer. 'You've never told me the sign for murderer.'

'Context.' Snapped Sherlock out loud and then he signed. Killler, Mugging. Murderer. Same sign. Same sign. Different lip pattern.

'What did he tell you?' Interrupted Lestrade slightly exasperatedly.

'Apparently red hearing aids make things sound better.' Sherlock saiad with a shrug. Strange child he signs.

What did you tell him? John asked.

Things. Is Sherlock's vague sign, which Lestrade interprets upon seeing John's confusion.

'What was that sign he did?' John asked mimicking the strange pinch and flick movement Luke had made up around his neck.

'Sign name.' Said Sherlock with a dismissive tone. Lestrade reached over and grabbed at Sherlock's collar flicking it up. Sherlock yelped and slapped Lestrade's hands away, before stalking off ahead of them. John turned to Lestrade.

'Sign name. ' He offered. 'A way to say someone's name in sign without having to fingerspell their name out. Usually something distinctive about how the person looks.'

'Oh.' Said John dully.

'Sherlock's calls me grey.' Lestrade says wryly, he formed a fist with his right hand and stuck his pinky finger out and rubbed it over his left fist. Grey.

'Ohhh.' Said John in realisation and then sniggered. 'Sherlock.' He said miming flicking his collar up. Soon both him and Greg were giggling which turned into full blown chuckles as Sherlock turned and threw what could only be described as a filthy look over his shoulder at them both.

'Oi!' Called John as Sherlock turned forwards again, John broke into a light jog to catch up with Sherlock. 'Hey.' He said placing a hand on Sherlock's shoulder. Sherlock shrugged him off and so John jogged on the spot in front of him, mimicking Luke's movements in the playground.

'What's my name sign?' John asked, loosely attempting the signs as he jogged backwards. Sherlock frowned at him, so John tried again, Sherlock's frown deepened. John was about to try again when Sherlock stopped suddenly and grabbed John to still him.

John stilled and repeated 'What's my sign name?'

Sherlock's expression cleared and then he shrugged and made to move off. But john stopped him. 'Come on, what's your sign name for me. I can take it. Sherlock!'

Sherlock stared blankly at John for a moment before his face slid into a slightly calculating gaze. Then he made a quick motion against the side of his head.

'Muppet. He called you a muppet.' Said Lestrade, who had now caught up with them.

John surpresses a desire to punch Sherlock, just. Something must have shown on his face because Sherlock steps cautiously out of reach.

Over the next week or so John spends a lot of time trying to goad a sign name out of Sherlock, who responds with an increasingly offence stream of supposeded sign names.

Cuddly.

Ancient man.

Jumper.

Limpy.

At one point Sherlock had rounded on John and said 'You know this is all terribly offensive. The mocking of this BSL convention – this is just what members of the Deaf community have to put up with all the time!'

John had simply retorted 'Whenever have you ever cared about that stuff!'

And then finally. 'John!' Sherlock had shouted one morning across the breakfast table. Both John and Mrs Hudson who was pouring the tea had jumped.

'I call you John.' Said Sherlock, 'Isn't that enough?'

'Well yes.' Said John and Sherlock snapped the newspaper open and held it up in front of his face.

And yes – I guess it was.