Gaining Light, a sherlock fanfic

Link to prompt can be found on my LJ

"My dear Watson, you as a medical man are continually gaining light as to the tendencies of a child by the study of the parents. Don't you see that the converse is equally valid. I have frequently gained my first real insight into the character of parents by studying their children."

—Sherlock Holmes, "The Adventure of the Copper Beeches

"Just leave the child with me while you are at work, John. I am perfectly capable of caring for another human being for an afternoon or two." Sherlock said dismissively.

"Are you certain, Sherlock? I mean, it would only be for a few days, just until the daycare has reopened. It wouldn't be an issue, but Mary is so excited to go back to work, and her replacement is going off on mat. leave now…"

"I'm sure. Besides, Mrs. Hudson will be just downstairs." John considered this. The fact did comfort him some. He nodded to himself.

"Yeah…yeah, alright. I'll bring him over before my shift tomorrow? I'll come a bit early to make sure you're all set."

"Excellent. Tomorrow, then. Now you'd best get home before Mary scolds you." He scoffed. John rolled his eyes before patting Sherlock on the shoulder comfortingly, understanding that the man was still a tad bitter that John had left 221B (even if it had happened well over a year ago).

John pretended he wasn't worried, but he wasn't fooling anyone. Sherlock nearly had to force him out of the apartment earlier that day, assuring him again and again that everything was fine. It hadn't been till Mrs. Hudson had echoed the sentiment that John had finally steeled himself against the inevitable and headed off to work.

That was why he was pausing hesitantly outside the door of 221B now. The flat was quiet. Too quiet. His hand rested on the doorknob. He took a deep breath and prepared himself for whatever (read: the worst [for either his son or for his friend]) he might find when he entered.

He could not have prepared himself for what he did find.

He had expected a disaster area in the flat, perhaps with dissected nappies, or comparative samples of more types of formula than were available in the UK. Alternatively (yet not actually any more likely), he thought he might find his crying son trapped in his playpen, with Sherlock ignoring him as he worked on whatever current experiment he had.

Instead, he found them asleep. Sherlock was draped across the couch on his back in his normal fashion, lips parted slightly in a silent snuffle of breath. Upon his chest (and his shirt stained with sick, John noticed), stretched out on his stomach, lay Hamish. His soother had fallen from his mouth, and had rolled to settle by Sherlock's neck. There was a dark spot of drool on Sherlock's shirt where Hamish's face was turned and rested comfortably.

John moved over and knelt beside the sofa. He ran his hand gently over his son's round head, brushing the blond, wispy hairs that grew there, and smiled to himself. Then he shifted slightly and ran his fingers through Sherlock's dark hair, combing some stray hairs back from his forehead. The man sighed, and turned his head into the caress, but then settled back into sleep.

He stood, checking the time on his wristwatch. The two of them would likely wake soon and cry out of hunger (Hamish, not Sherlock [probably]). Considering this, he wandered into the kitchen and peered into the fridge, taking out one of the bottles of pumped milk Mary had prepared and setting it into a pan of water to warm. Then he went about preparing food for Sherlock and himself. He could wait to eat with Mary when she came home later, but he missed having supper while watching crap telly with Sherlock, and the once a fortnight or thereabout that they managed to do so wasn't really cutting it for John (or Sherlock, but he kept quiet about it).

When the bottle was sufficiently warmed and with a simple meal of pasta prepared and put into dishes, John went to wake Sherlock and Hamish. He slipped his hand between the two to lift his son into his arms, waking him in the process. He looked a bit cross at being woken, and let out a small distressed cry. Sherlock woke immediately at the sound, his eyes open, aware, and a bit frantic. When he spotted John and Hamish, he calmed and smiled up at them.

"Sleep well?" John asked, moving away from the sofa to grab a bowl and offer it out to Sherlock. The man sat up, accepting the food with a hungry look. John took his own food and the bottle and sat down beside Sherlock.

"Surprisingly so. I think it has something to do with the scent of babies; it seems to incite certain feelings. Not enough data to say for sure though. Not to mention that any data is quite subjective." He said around a mouthful of food.

"Are you saying my son smells good?" John chuckled, "You must be lucky then, it's not always so." Sherlock huffed a bit, but did not otherwise respond to the comment. When he finished his food, he held out his arms to take Hamish and the bottle from John so that he could eat his own meal. John turned on the telly and pretended to pay attention to what was playing there, but in actuality, he was watching Sherlock and Hamish out of the corner of his eye, taking in the smile Sherlock bestowed upon the baby (a smile of a calibre that normally only John was privy to). When the three of them had finished eating, John took the dishes and the empty bottle to the kitchen to clean them. In the sitting room, Sherlock held Hamish to his shoulder and patted his back (John assumed the shirt was already done for).

John gathered up Hamish's things, putting them into the diaper bag which went everywhere Hamish went. "Mary will be home soon." He commented, "We should be on our way." He reached out for Hamish, and Sherlock looked very reluctant to give him up, but he moved closer to tuck Hamish into his father's arms, taking a moment to bend down to press his lips to the top of his head. Hamish cooed happily from where he was held between the two men's close bodies. John hid his surprise behind laughter "One for me, too?" he prompted, bowing his head. Sherlock made a small sound which seemed equal parts amused and offended by the idea that he was being teased for his action, but he gave John a quick kiss on the top of his head anyhow, before ushering them out the open door.

That Friday, Mary and John went to Angelo's after work, Sherlock having convinced them that they should all go out for dinner. Sherlock and Hamish were already there, seated at the normal table. Angelo had Hamish lifted high in his arms, speaking gibberish which seemed to please the baby to no end. When they approached the table, Angelo turned to them.

"John, your son takes after his Zio Sherlock, no?" he handed Hamish back to Sherlock.

"I think we cursed him by naming him Hamish Holmes Watson." Mary commented as she sat down, a stiff smile pasted on her face.

Angelo took Mary's order, promising John and Sherlock their usual fare before disappearing into the back of the restaurant.

"Daycare would be entirely inappropriate for Hamish." Sherlock said suddenly. John and Mary both stared at him, but said nothing. "They will not know how to treat him or what he needs. For instance, they will not understand that his cries are higher-pitched when he is lonely, 20 decibels louder when hungry, and last an average of 14.28 minutes longer when he is tired. You should just bring him to me when you are both at work." He explained quickly. Mary glanced at John worriedly.

"What about when you have a case, Sherlock? You won't want to miss out on anything exciting because you have to stay home and watch the baby." John pointed out.

"Mrs. Hudson is just downstairs; I spoke to her about it today, and she agreed with me. Should a lengthy case come up, I'm certain you can make arrangements. Mary's sister would be happy to take care of Hamish once in a while, and she works from home, so it wouldn't be an issue." Though they didn't really want to admit it, Sherlock did have a point.

"I suppose that would be alright." John said before turning to his wife. "What do you think, Mary?" she wouldn't meet his eye, but she shrugged and gave a bit of a nod.

"Excellent." Sherlock beamed at them, then turned his smile down at the baby in his arms.

It took John a couple of weeks to notice, but when he finally did, he was overwhelmed by the sheer number. Strewn about the whole flat were sheets of paper documenting everything about Hamish, from his growth every day (numbers recorded to the hundredth), to the times he slept, woke, ate, required changing, his mood (based on diet [formula vs. breast milk], fabric [apparently Hamish preferred silk to cotton {John blamed Sherlock for this}], day of the week, etc.), the colours of different patches of skin and hair in reference to 3 different colour dictionaries, CSS, and HTML coding, and hundreds of more pages which John didn't even attempt to understand. He mentioned them to Sherlock.

"Hamish is fascinating, John, and my data on infants is lacking. I'm simply making up for this fact while caring for your child."

"Right." John sounded skeptical of this.

"John! He sneezed!" Sherlock spouted cheerfully, jumping up to grab a tissue, but stopping to note the occurrence on a piece of paper before wiping the baby's face.

"Yeah, babies do that sort of thing." John remarked, amused by Sherlock's antics. He wasn't sure that he'd seen Sherlock so entertained by another human being since Moriarty.

"And see how he observes everything?" Sherlock said, and John and he looked at the way Hamish's big eyes took in everything around him. "I wonder if a person's skills of observation and deduction are dependent upon their raising." He mused. "Judging by Hamish, I would hypothesize that we are born observing and deducing, but grow out of it. Or perhaps he is just particularly extraordinary." John didn't comment on this. Sherlock's fascination with every detail about Hamish wasn't bothering him or Hamish at all. Mary had voiced a vague worry that spending so much time with Sherlock might make their son "strange", but John dismissed the idea. He thought it was rather good for him (good for Sherlock, that is).

It was bound to happen sooner or later. Sherlock was in one of his dark moods. Hamish was in a mood highly reminiscent of Sherlock's dark moods. So John had to beg off work early to rush back to 221B to save either Sherlock, or Hamish – it was not entirely clear who really needed saving.

"He's worse than you, begging for me to pay the utmost attention to him. I have things to do, John! I can't just stare at him and shake his bear at him for hours on end!" Sherlock ranted, half-shouting so he could be heard over Hamish's babbling. John considered protesting that Sherlock was the one who demanded attention rather than him, but decided it wasn't the right time for that argument.

After a brief discussion where they agreed that Hamish could come back tomorrow while John worked (he just needed time today), and Sherlock kissing the top of both Hamish and John's heads, John took his son home and spent the rest of the day enjoying his new-found time off and showering Hamish with attention (and if it reminded him of keeping Sherlock occupied, he wasn't going to mention it).

Hamish kept making the same motion with his fist over and over. John, head tilted to the side, studied him curiously. Hamish looked back at his father expe ctantly and continued to do the motion.

"Mary?" he called out, "What is Hamish doing? Have you noticed this before?" Mary popped her head into the room and looked at Hamish.

"Oh, yeah, I've noticed him doing it, that, and a couple other motions. I think it's baby sign-language, you know, like they talk about on the telly."

"You think it is? You mean you didn't teach it to him?" John turned and looked at his wife in confusion.

"No, I assume Sherlock has been teaching it to him." She said a bit darkly. "You'll have to ask him what it means, because I haven't a clue." She left again.

John sent Sherlock a text. Mary was right, Sherlock had taught Hamish a few different signs. Apparently Hamish wanted to be fed. He passed him off to Mary, explaining this to her.

"Seems a bit early for him to be doing signing, isn't it?" he asked her. She looked at him pointedly before nodding in agreement.

He could hear the sound of the violin before he entered the flat. It wasn't anything he recognized, and by this point, he was able to recognize most things Sherlock played. He found Sherlock by the window, standing before the music stand, playing the violin while watching Hamish's form where he lay sleeping in his playpen.

"That's a lovely piece." John commented when the strains died down.

"It's a lullaby." Was all Sherlock said.

Before he had Hamish left, John took a peek at the sheets of music sitting on the stand, wanting to know what Sherlock had played. He found a haphazard stack of paper with empty staffs, and a few pages with musical notation written-in with blue fountain ink. The pages were numbered in the upper right-hand corner, and at the top of the sheet numbered '1' was the name 'Hamish Holmes Watson' in Sherlock's distinctive script.

Smoke was seeping out from the under the door to 221B. John burst through the door, prepared to save his friend and son, but halted when he found Sherlock standing at the kitchen table mixing fluids in beakers, and Hamish in a chair, clapping his4 pudgy hands excitedly.

"Again!" Hamish cheered in childish glee. Sherlock grinned at him before adding some powder to a beaker, whose contents turned bright pink before emitting a large puff of smoke from the top. Hamish laughed so hard he nearly tipped out of his chair. Nobody seemed to be in danger (even if Hamish was gasping for breath for all his laughter), so John made no complaints.

"Mary will be here soon." John told Sherlock. "I just…I just want to talk to Hamis before she arrives." Sherlock nodded understandingly before shutting himself in his bedroom so that John and Hamish could talk in private in the living room.

"Come here, Hamish." John said, patting a spot beside him on the sofa. Hamish put the book he was reading (forensic science; John was never done being surprised by how clever his son was for one so young) away on the bookshelf, and sat by his father. "I wanted to talk to you about mummy and daddy. Things are going to be different, you see…" he trailed off, trying to decide how to approach the subject. He'd been thinking about it all day, barely paying attention to his patients. How did one break it to a kid that his parents were separating?

"I know, Daddy." Hamish told him in all seriousness. John paused and looked down at him.

'You…you do?"

"Yes, Sherlock explained it earlier."

"He did?" John was gaping. Hamish gave him a look that perfectly mimicked Sherlock's idiot look.

"Yup. Then he taught me about family law. Then Mycroft stopped by and made him angry. Then we ate ice cream. Then we made the bed up in your room, even though we both hate making beds. Then we-"

"Wait, wait." John interrupted Hamish's spiel. "You made the bed?" he questioned. The idiot look reappeared.

"We thought it would be nice to have your room ready for you. He said it is just like it was before, when you lived here."

"I…see." John said slowly. He stared at Sherlock's closed door as though it might give him some clue as to what the man inside was up to. It didn't.

"Daddy? Can I go back to reading now?" Hamish asked politely, startling John out of his thoughts.

"Of course. Give your ol' da a hug first." Hamish obediently tucked himself into his father's arms and squeezed. "I love you, Hamish." He murmured into his son's blond hair.

"I love you, too, Daddy." He replied, then went to recollect the forensics book from the shelf and picked up where he had left off.

Part of John wanted to pound on Sherlock's door and demand to know what was going on (and perhaps thank the man for saving him from explaining things to Hamish), but he'd had his fill of confrontations recently.

Eventually, Sherlock reappeared, picking Hamish out of his chair, but setting him upon his lap so that they could read the book together.

When Mary appeared to take Hamish home, John wished he could simply hide in the kitchen.

"So, shall I bring Hamish here to spend the day with Sherlock before I leave for work tomorrow?" she asked. John hesitated. They'd not actually discussed how it would all work; they'd been too busy trying to keep their arguing secret from Hamish.

"Yes." Sherlock jumped into the conversation. "I'll continue to watch Hamish while you two work. And bring him here Thursday as well. John has the day off, but he'll be staying here, right, John?" he rested his hand upon John's shoulder. John looked up at him gratefully, nodding in response. A flash of anger crossed over Mary's face as she looked between the two men.

"Very well. " she said, taking Hamish's hand within her own. "Say good bye, Hamish." She instructed.

"Bye, Daddy. Bye, Sherlock. See you tomorrow." He said, sounding a bit sad that he was leaving them. Sherlock stooped down to kiss the top of Hamish's head, then ruffled his hair.

"Tomorrow." John and Sherlock both said in confirmation before the door shut behind Mary and Hamish.

John sighed and leaned against the wall, rubbing at his forehead. There was heat building up behind his eyes, but he didn't want to cry while Sherlock stood right beside him. He felt Sherlock move closer, then slight pressure on his head and Sherlock pressed his lips against his hair.

"Hungry?" Sherlock asked as he withdrew.

"Starving." John replied.

"Daddy, is Sherlock your boyfriend?" Hamish asked. John nearly dropped his cup of tea on his lap.

"Wh-what? Why? Where did this come from all of a sudden?"

"I asked Sherlock about why Aunt Harry was here crying about a lady named Clara, and he talked to me about human sexuality and relationships. I asked him if you were boyfriends, but he wouldn't answer me. He said it wasn't his area, and that I should ask you." Hamish replied, matter-of-fact.

"No, Hamish. Sherlock and I are both boys, and we are friends, but we aren't boyfriends." He wondered if he should have a word with Sherlock about age-appropriate subject matter, but with a son as precocious as his was, he didn't think it would make much of a difference.

"Are you sure?" Hamish asked with a distinctly Sherlockian skeptical tone. "You live together and do everything together and have fun together." He pointed out.

"I'm sure, Hamish. We're just friends." Though he'd had this exact discussion many times, he had never imagined he would have it with his own son.

"I know now that you are Sherlock are not boyfriends, Daddy." Hamish said one night. He was spending the weekend with John, who did not have to work for a few days. They were both tucked into John's bed, having finished reading a bedtime story (a mystery bedtime story which Hamish had solved ¾ of the way through, much to John's amusement [and horror]).

"Oh?" John said sleepily.

"Yes. You and Sherlock don't sleep in the same bed, like Mummy and her boyfriend do." Suddenly John wasn't feeling very sleepy at all.

"I see." He said simply. He wanted to grill Hamish on details about this boyfriend (about whom he had not even known of until this moment), but Hamish yawned in a manner that meant he would be asleep within the next 15 minutes, as Sherlock had pointed out to him several months before.

He waited till Hamish fell asleep, then went downstairs to make himself a cup of tea. Sherlock was still awake, laying on the couch texting someone furiously. He glanced at John as he walked past.

"I'll have a cup too." He said. John grunted at him, but he took down two mugs from the cupboard.

"So he mentioned Mary's new beau, did he?" Sherlock asked when John placed a cup near his head on the coffee table. He lifted his legs, offering John a place to sit on the sofa, dropping them down onto his lap as soon at John was settled.

"Yeah." He confirmed. "I don't really want to talk about it." So Sherlock said nothing more.

They remained in companionable silence. Sherlock's presence was enough to slow John's racing thoughts about Mary and the mystery man, and he found his eyes growing heavy. He vaguely noted that Sherlock eventually put his phone aside, and dragged his half-asleep form down to stretch out beside him. He was going to protest, but he found that he was too warm, too comfortable, and too tired to do so.

"Good morning!" Hamish said cheerfully, in the few seconds between John waking and actually opening his eyes. He jolted a bit, which made him aware that he was being restrained. When a soft snore tickled against his ear he realized that the restraints were Sherlock's arms twined about him as they lay together on the sofa. He tried to wiggle out of Sherlock's grasp without waking the man, but to no avail. The arms tightened around him momentarily, before releasing as Sherlock rolled away and strode into the bathroom.

"Good morning, Hamish." John said rubbing the back of his neck as he stood. He could see that Hamish had questions burning behind his eyes. "What do you want for breakfast?" he asked as a distraction.

"Hamish tells me you and Sherlock are boyfriends." Mary said from across the café table. She never broke her gaze as she lifted her cup and sipped her coffee.

"Yeah, well…he said you have a boyfriend." He deflected "and that you sleep together." He added "You might want to keep the more intimate facts of your relationship away from our son. I know he acts older than he is, but he's still a little boy."

"I know, John, I know." She sighed in exasperation. "He just saw Tom coming out of the bedroom early one morning. I hadn't intended for him to find out that way, they'd only met twice…" she trailed off. John could see that she was sorry about it, so he couldn't really fault her for it too harshly.

"That's part of the reason why I wanted to talk to you though." Mary said. "You see, Tom and I have been dating for a while now, and he asked me to move in with him. His apartment is closer to my work, and it would save us both money. It's a nice neighbourhood too." John waited for the catch. "But I'd prefer for Hamish not to switch schools in the middle of the year; he likes his school, and he has friends talked about finding another place, but then Hamish told me about you and Sherlock, so I figured you have an empty bedroom now, and Hamish could stay at his school. I know you miss Hamish when he's not around – he misses you too – so I just thought maybe you might want him to live with you and Sherlock." She finished. "What do you think?"

John opened his mouth to speak, then closed it again. He repeated this process a couple of times, trying to decide where to begin. "Sherlock and I aren't –" he began, for that seemed as good a place to begin as any, but Mary interrupted him.

"It's okay, John. I understand. I always knew that you and Sherlock had something special; I could see it before we even got engaged. A foolish part of me thought that once we were married you would love me more, but we both know that could never be. You don't need to keep it a secret. I am happy for you though, John, really." She smiled and covered John's hand with her own. "I don't know that I believe in soulmates, but even if such a thing doesn't exist, you and Sherlock are about the closest things to them out there."

"I-" Mary had more or less rendered him speechless.

"You don't need to answer now. Discuss it with Sherlock. I won't be moving for nearly a month anyhow. Once you know, we can decide what to tell Hamish." She smiled and squeezed his hand. "I really do have to run though. If I don't leave now, I'll be late getting back to work." She grabbed her jacket and handbag off the back of her chair, bidding him goodbye and kissing the top of his head as she swept out of the café. He scratched at his head where she had kissed him. Nobody but Sherlock kissed the top of his head.

Hamish had caught a cold. John suspected it was a bug he had brought home from work, but he pushed down the guilt and focused on making his son feel well again. He'd expected Sherlock to avoid Hamish like he was a leper, but he took as much of an interest in Hamish's health as John did, even ordering soup from their favourite Chinese restaurant.

Sherlock stood close behind him as John tucked Hamish into his bed, telling the boy that sleep would help him become well again (for the child had as little interest in rest as Sherlock did).

"Mummy and Tom always give me a kiss after tucking me in." Hamish said, petulant for his sickness.

"You're not normally ill when they do that." John responded awkwardly. The mention of Mary and her boyfriend reminded him that he'd not talked about Mary and his café conversation yet.

"Don't care." Hamish pouted. John sighed, but bent down and gave his son a quick peck. "Now you." Hamish ordered Sherlock. Sherlock obediently followed his instructions, kissing the top of Hamish's head and then his forehead in a tender manner that warmed John's heart. "Now each other!" Hamish cried with a somewhat evil glee. John's jaw dropped, but Sherlock simply swept in and rested his lips against the top of John's head, then shifting down and capturing his parted lips in a kiss. Before John could react, it was over. Hamish nodded approvingly and snuggled himself further down into the cover. "Good night." He mumbled, closing his eyes, clearly ready to go to sleep now that his demands had been satisfied.

Sherlock and John went downstairs, having tea and sitting in front of the telly, fighting quietly over what they should watch (Sherlock insisted he could not bear to watch even one more Bond movie). Eventually, Sherlock stood, stretched, and declared that it was time for bed. John murmured 'good night' but did not move. He planned to make do with the sofa for the night, so that Hamish could have the full bed while he recovered. Sherlock did not walk to his bedroom though, but rather, stared down at John expectantly. "Well?" he asked, offering his hand down to John. John blinked at him. "Hamish informs me that boyfriends sleep in the same bed together." Sherlock continued, giving up on waiting for John to take his hand, and grabbing the one closest to him instead. He simultaneously pulled John up from his seat and turned off the television.

"Oh." Was all John could think to say. Sherlock didn't seem to mind, for he simply smiled and walked John into his bedroom.

"Wha' time is it?" John asked groggily, only half alive. Sherlock pulled him tighter against his chest.

"Not time to get up yet." He mumbled, nuzzling his face into John.

"Mmmm. Kay." John smiled, and ran his hand up and down Sherlock's bare back. He considered letting his hand drift lower over Sherlock's (also bare) bum, but he was far too comfortable to prompt any lazy morning sex (yet, anyway).

"When Mary comes to pick up Hamish tomorrow, tell her that he can move in upstairs as soon as they are ready." Sherlock informed him after a bit.

"Ah…okay." John refused to ask how Sherlock knew, because he felt fairly certain that Hamish was involved, and he didn't want to know what his son did and did not know about any off this.

"Hamish couldn't wait to come home." Mary informed him. "Apparently Sherlock promised to take him to the morgue?" the worry in her voice was evident.

"Yeah." John laughed. "Don't worry, he just wants to show him the equipment and things. No corpses, I promise."

"He'd probably want to do a dissection if he saw one." Mary sighed, but she didn't sound overly concerned. They'd both come to accept that perhaps naming Hamish after Sherlock really had cursed him.

"Come on, John! Case!" Sherlock shouted excited from inside the flat.

"Yeah, come on, Dad, hurry!" Hamish chimed in. They approached the door, and Sherlock thrust John's coat at him.

"Not to worry, Mary. Just a robbery, no danger at all." Sherlock quipped.

"Don't give me that, Holmes." She replied, "We all know that none of you would be headed out there if there wasn't at least a little danger." Sherlock shrugged. "If John and Hamish don't make it back safe, I'll have your head." She threatened, the same threat she made every time the three of them went on a case. They had agreed that Hamish could accompany them on minor cases, only the ones that were not wholly inappropriate for a child.

"Bye, Mum!" Hamish said as he rushed out the door, followed by Sherlock, who paused to drop a kiss upon Mary's head. John mimicked Sherlock's action as he shut the door behind them, Mary heading for Tom's car, and Hamish, John and Sherlock waiting as a cab pulled up to them.