A/N: This is… this is shameless Christmas fluff. Is fluff the right word? I don't think so. But I just have so many feels for the awkward relationship between Sherlock and Mycroft and once this was in my head, I just had to write it. Really, I thought I had given up fanfiction writing for good, and then I did Legends (Shameless plugging, yep) and people seemed to like it, so I thought maybe some more Sherlock stories were in order… Anyway, enjoy :)

Childhood Relics

It was a few days before Christmas and, with help from John, Mrs Hudson had finished decorating their Baker Street flat with fairy lights and a tree. Sherlock had complained but, on seeing it was inevitable, had fussily rearranged all the decorations that were too close to his things, which was his version of getting into the festive spirit. Mrs Hudson had just gone downstairs to get them a bottle of wine, and so John thought it was her tread coming up the stairs.

"That was qui-" He began, but it died in his throat when he saw it was not Mrs Hudson but Mycroft Holmes coming up the stairs. "Mycroft."

"Good evening John, Sherlock." He said, stepping inside. He was carrying a small holdall, a kind of overnight bag. John really hoped he was not coming to stay, but given that it was Mycroft, it didn't seem likely. Sherlock was looking at his brother, puzzled.

"You aren't here about a case." He said, reading something in Mycroft's demeanour that was invisible to John, though no doubt obvious to him.

"Correct." Mycroft answered. "I-"

"Don't care, go away." Sherlock dismissed, flopping down on the sofa with theatrical indifference.

"Now now." Mycroft smiled tightly. "I bring good tidings of great joy." He dumped the bag down on the kitchen table with a thud.

"What is that?" Evidently Sherlock didn't like not being able to tell at a glance. He was eyeing the bag with such suspicion that it might as well have been a bomb. For all John knew, it could be.

"I have been waiting almost a decade for you to remove your belongings from my loft. I thought I would help."

"Why, do you need the space for your unused gym equipment?" Sherlock asked. Mycroft sniffed but said nothing. Sherlock turned to John. "It's not even his house." He said, as if this settled the matter. "It belongs to our parents."

"Belonged. I inherited it when Mother moved out."

"Now, there's a surprise."

"Sherlock likes to pretend he had a troubled upbringing." Mycroft said to John with an air of confidentiality. "As opposed to the reality, which was that he went to the best public schools and university and that our parents spoilt him rotten. If I hadn't been there…"

"Oh, yes." Sherlock interrupted venomously. "How lucky you were there." He gestured at the bag. "You can take those and burn them."

"At least look through them first." Mycroft said tiredly. "Then you can dispose of the rest. Merry Christmas, brother." With that he left, heading downstairs. John heard Mrs Hudson catch him, try and convince him to stay for a drink. John doubted it would work, no matter how much she said he should see more of his brother. John highly doubted Sherlock wanted to see more of Mycroft anyway. With a long-suffering sigh to show how put upon he was, Sherlock went over and rooted through the bag, finally pulling out a rather old, rather battered, hard backed and illustrated copy of Treasure Island. He turned it over in his hands, looking rather pleased in spite of himself, and carried it away to the settee.

"Tell Mycroft he can get rid of the rest." He instructed, lying back and opening the book.

"Sherlock, you haven't even looked properly." John said, taking advantage of Sherlock's distraction to go and look inside himself. There wasn't much, just a few Meccano construction kits and old music books which didn't look particularly well used. John wasn't surprised; Sherlock was just the sort who would have learnt to play predominantly by ear and instinct. He pulled the Meccano boxes out into the light to inspect them more closely.

"Ah, you had the space station?! I always wanted one, but it was too expensive!"

Sherlock looked at him, amused. "You can have it if you want, John."

John did want it, but his pride couldn't accept it. He put it back into the bag but as he did, his fingers brushed against something soft at the bottom, almost buried in the books. Frowning, John began to try and pull it out.

"I never made those kits." Sherlock commented. "I just used the pieces; there's no point if you don't build for yourself. All the parts are in the right boxes though, John, if you want to play."

"Of course, because a man who indexes his sock drawer would, as a boy, have kept his Meccano in order. It all makes sense now." John finally succeeded in extracting the soft thing. "And what's this?"

"That," Sherlock pointed at it accusingly "Is the incarnation of every lie Mycroft ever told me when I was a child."

"Really? Because it looks more like a stuffed reindeer." John looked it over. "With an eye patch."

"I went through a pirate phase." Sherlock said, without a hint of shame. "The eye had to go."

"Of course it did." John laughed, looking around a little and then finding a place to stand the plushie on the mantelpiece.

"Don't put him up there!" Sherlock said, embarrassed now.

"Him?" John repeated, trying not to laugh.

"It."

It was too late. "Don't worry, Sherlock." John laughed. "People will just think he is a Christmas decoration. So, does he have a name?"

"Malvolio." Sherlock answered, sullenly.

"Ah, of course, the natural name for a reindeer." John made himself smother his laughter, knowing this was one of the rare times he might find out something from Sherlock's past. He didn't want to make him clam up again. Still, he struggled to keep a straight face. "So, what did Mycroft lie to you about?"

"Christmas."

"Christmas." John repeated, sceptical. "Right."

"Father Christmas." Sherlock elaborated, frustrated now. "He told me Father Christmas was real!"

John couldn't help it. The anger in Sherlock's voice made it all the funnier. He gave up and gave way to hysterics. "W-what?"

Sherlock, however, was clearly offended and without another word disappeared into his bedroom, taking Treasure Island with him. John suspected it would be finished before he came out.

oooooooooooooooooo

Sherlock, at age three, was already something of a scientist; though he preferred the term adventurer. The day had been spent reasonably productively learning about tracking skills; the snow throughout the grounds had fallen the day before and had frozen overnight, thawing slightly in the weak noon sunlight, meaning it was perfect for leaving footprints. Sherlock had successfully tracked Mycroft, the gardener and the nanny (who had not succeeded in tracking him) and then had proceeded to make a catalogue of different prints, running, walking, jumping, hopping, tip-toeing and others, first in wellies and then in socks and then in bare feet, at which point the nanny had finally found him and scolded him, making him put his wellies back on and then saying he had to go inside at once.

"I'm not finished." Sherlock scowled. "The snow will be too slushy tomorrow!"

"Tomorrow?" The nanny said. "Oh, you silly thing. You won't be out here tomorrow. Tomorrow is Christmas!"

"I can't go outside on Christmas?!" Sherlock said, horrified. "I hate Christmas."

"But don't you want to see what Father Christmas brings you?"

"Father Christmas isn't real." Sherlock said scathingly. "Getting all round the world in one night is impossible even in a rocket if you're stopping at every house. You're old enough to know better."

For a moment the nanny gaped, not sure what to say. As usual, she reverted to her failsafe- scolding him. "Well, you're old enough to know better than taking your wellies off in the snow!" She said. "You'll catch cold!" And she made him go back to the house and have a bath straight away.

After his bath it was bed time. Sherlock did not like bed time, but he particularly did not like having to go and say goodnight to his mommy. She was in their large lounge, arranged on a small settee, reading by the light of their wood fire and the Christmas tree lights. The room smelt of pine, both burning and living. Sherlock always felt too small in such a grand room, and silly in his slippers and dressing gown. He was going to get this over and done with as fast as he could.

"Goodnight, mommy." He said, putting a toe over the threshold so he could say he had been into the room, then quickly turned and left. He was still too late. He could feel his mother's frown through the back of his skull.

"Sherlock? Come here, darling, and say goodnight properly." Reluctantly, Sherlock went over to her and she engulfed him in her arms. Her pashmina jumper prickled his skin, and he wanted to scratch at it like a cat, but he didn't like playing in front of people, so he stood stiffly. She kissed the top of his head. "Goodnight, darling. Be good and go straight to sleep, or Father Christmas won't come."

Sherlock frowned, surprised at his mother. "Mommy, Father Christmas isn't real."

"What? Don't be silly, sweetheart, of course he is." His mother smoothed his hair, nervous. "He lives at the North Pole with all his elves to help him build the toys, and then he puts them all in his sleigh and flies with his reindeer-"

"Mommy, if he was going to get around the whole world in one night, he would have to go really fast, right?"

"Well, yes, I suppose, but he can-"

"But when things go fast they get really hot, so they would all explode!" Sherlock threw his arms wide, adding some sound effects to try and make her see his point. "He would get through a lot of reindeers. And sleighs. And he'd be dead."

"Oh, alright, Sherlock!" His mother snapped. "Just go to bed, it's a big day tomorrow, whether Father Christmas is real or not!"

She was upset. Sherlock frowned. She was irritating and stupid, but he didn't like it when she was upset. "Don't worry, mommy." He tried. "He's not real, so he can't explode."

"Thank you, Sherlock." She sighed. "Sleep well, darling."

She still seemed sad, but now he had tried Sherlock had fulfilled his obligation as far as he was concerned. He went to bed, allowed the nanny to tuck him in, and did his daily count to three hundred to make sure the coast was clear. Then he got up, went under his bed for his Meccano, and tipped it out over the bed, sorting the gears and connectors and tubes into sizes, shapes and colours because he hated not being able to find what he wanted easily. He was working on building a catapult, but the plastic wasn't flexible enough to be elastic, so it was trickier than he had anticipated. He didn't make much progress that night, distracted by the disturbing conversations he had held with the adults. He didn't understand how they could all believe in Father Christmas when it was clearly such a ridiculous fairy story. He was greatly concerned by the only working hypothesis he could come up with; that everyone got stupider once they were grown-up. He hoped that wasn't true, but decided that in the morning he would come up with some strategies to keep his brain working properly forever. An hour and a half later, Mycroft came in. It wasn't fair, he got to stay up later and nobody went into his room to make sure he actually went to bed, so as far as Sherlock was concerned, could stay up as late as he wanted. But then he was older, in the top year at their day school; almost grown up. Sherlock couldn't help but think it would be a shame if his brother got stupider, because at the moment Mycroft was at his intellectual peak. Mycroft knew everything, which as far as his little brother was concerned, was a blessing and a curse. On the one hand, he could answer any question, and Sherlock always had lots of questions, about everything. On the other, he was always right and Sherlock never was, never. No matter what Sherlock tried to confuse him with, Mycroft knew everything.

"Are you still working on the catapult?" Mycroft asked, as Sherlock shuffled across the floor to let him look. "It's not going to fire very far like that, Sherlock, you need to make the arm longer."

Sherlock scowled, but began to dismantle his construction.

"Save it for now." Mycroft said. "It's time for bed. Come on, you don't want to be tired and do shoddy work." He started to remove the parts from the covers. Sherlock shoved him aside and did it himself; when Mycroft helped he always put things in the wrong boxes and then Sherlock couldn't find them again. When all the parts were safely stowed, he wormed in under the covers.

"Good boy." Mycroft said in a way that Sherlock hated. "Now, go straight to sleep or Father Christmas won't come."

Sherlock sat upright, alarmed. It wasn't possible. "But Father Christmas isn't real!" He looked at his brother with something almost like fear, wondering if Mycroft was already losing it.

"Of course he is." Mycroft said, scornfully. "Didn't you know? I thought mommy had told you."

"But… but… it's impossible!"

"Why is it?"

"Because… because he can't go that fast! He'd burn up!"

"Sherlock, I can't run as fast as you." Mycroft shrugged. "Father Christmas can just do things that you can't. That's logical enough, isn't it?"

Sherlock frowned, thinking this through. "I suppose so… but doesn't everything have to obey physics?"

"Only physical things." Mycroft answered. "Magical things only have to obey the rules of magic, and Father Christmas is very careful not to break any of them."

"Oh." Sherlock said. "What are the rules of magic?"

"Not now." Mycroft sighed. "It's getting late. But the main one is that you have to have a very high body temperature."

"Really?"

"Yes, that's why Father Christmas only comes in winter; in the summer it's far too hot for him to leave the house."

Sherlock was almost convinced. After all, Mycroft seemed to know what he was talking about. But there was one more thing that didn't make sense, one last trump card Sherlock could play. "Mycroft," He said. "If Father Christmas is real, does he really have a naughty list and a nice list?"

"I believe so."

"And the naughty children only get coal?"

"Yes."

Sherlock grinned, hardly able to contain his excitement. For once, Mycroft was wrong after all. "Then why do I get presents every year?"

Mycroft, however, did not fall to the floor weeping his defeat. Instead, he just raised his eyebrows, leant forward and said, "Because daddy pays him off, of course."

And with that, Sherlock's disbelief crumbled and he could no longer see how the existence of Father Christmas could be denied. He pondered, wide eyed.

"I want to see him!" He declared, like all good scientists seeking proof.

"Alright." Mycroft said. "I'll come and get you at midnight, mommy will be in bed by then. We'll go and hide behind the settee and lie in wait. Until then, we should get a little sleep, we need to be alert."

It was a good plan. Sherlock settled down and made himself go to sleep, so he would be well rested for his adventure; but when he woke up, Mycroft was shaking him and the room was already full of daylight.

"Mycroft!" Sherlock said accusingly. "You said you'd get me at midnight!"

"I'm sorry, Sherlock, he must have heard us talking." Mycroft said, tutting. "He put us to sleep with magic. But look, he left you something." He handed his brother a parcel in Christmas tree paper. "I think it's because you didn't get to see the real ones."

Sherlock pulled the paper off to find a toy reindeer, which would become a staple of his childhood for the next four or five years. For the first few days, he left it on a chair next to his bed, and watched it carefully, waiting to see if it did anything, reasoning that a magical present had to hide some secret; especially when his father's donations were probably paying Father Christmas' rent, he would want to stay on their good side. The reindeer, however, didn't seem to exhibit any immediately obvious magical powers, so Sherlock took to carrying it around and letting it sleep in his bed, in order to observe it more closely. He also named it and took it along on his adventures, just in case. It was worth talking to a magical toy, he reasoned, because one day it might talk back. You never knew. After all, people were always saying Christmas was magical, and that meant it didn't have to obey the laws of physics.

oooooooooooooooooo

After Sherlock had gone off in his huff, John had emptied out the bag, intending to stash the childhood relics away until Sherlock was in the mood to go through them properly. Mycroft was still in the hall downstairs, so John followed.

"Mycroft, your holdall." He said, giving it to him.

"Thank you, John. Happy Christmas." Mycroft turned to go, but John had a question for him.

"Sherlock said you told him Father Christmas was real."

"I did."

"Okay, why?" John asked. "I take it you never believed it yourself."

"Of course not." Mycroft frowned, picking imaginary dirt from his coat sleeve. "The whole thing is patently ridiculous. That's why I told Sherlock it was true. It was an experiment to see how long a mind as clever as his could be deceived."

"Right. So it was an experiment, and nothing at all to do with wanting to give him some ordinary childhood joy?"

Mycroft sniffed and turned dignifiedly, declining once again Mrs Hudson's invitation to stay, and headed out of the door.

"Bye, Mycroft." John said. "Merry Christmas." Sometimes, when it came to the Holmes brothers, it was pointless to even try.