Disclaimer: Sherlock Holmes and properties are owned by Sir Arthur Conan Doyle. Sherlock and properties are owned by BBC One, Mark Gatiss and Steven Moffat. Harry Potter and properties are owned by JK Rowling. I don't make money from writing this fanfiction. The story contains spoiler for both Sherlock and Harry Potter.

Winter Tale

Chapter I

It was Christmas already. This year was the second year John Watson celebrated Christmas with his flatmate and also best friend, Sherlock Holmes. Yes, the very same Sherlock Holmes who faked his death for three months, leaving John quite devastated.

Of course, he understood the reason behind it. Jim Moriarty's henchmen would kill them all if there was a wind if Sherlock was still alive. So, Sherlock needed to pretend that he was dead while working to bring down the Moriarty's men. However, that didn't mean he would accept Sherlock back without some retribution for worrying him. He punched Sherlock in the face and broke his nose in the process. The man deserved it.

It was huge in the newspaper when Sherlock finally came back to among the living. The very same newspaper who called Sherlock liar a few months ago. In fact, many producers and also publishers contacted Sherlock and offered him deal either to make movie or books based on his experience. Sherlock rejected them all.

John was really glad that his friend was back. And no, despite everything people had said about them, they weren't a couple. They were merely best friends who shared the same flat together.

Life returned like usual. Detective Inspector Lestrade would call them whenever there was case police couldn't solve. John would blog about it. Private clients who read the blog would come to hire Sherlock. All was well.

And now it was Christmas time. John had planned party at 221B Baker Street. He had invited Lestrade, Molly and Mycroft. Mrs. Hudson wasn't really guest anyway. It was party for their small circle of friends. Mycroft didn't really fit the category but he was Sherlock's brother. Speaking of it, the whole time Mycroft knew that Sherlock was alive and helped his brother in secret. When John thought about it, it was weird that Mycroft would let those rubbish papers to besmirch his younger brother. He was the British Government, for God's sake, stopping one article from being published wasn't a big deal at all. But, it was all in their plan to fool Moriarty.

Well, that was in the past and now John had many things to do. The first thing was to ensure the party went perfectly. As perfect as it could be with Sherlock's presence. Amazingly, the man so far accepted what John planned for Christmas without once arguing with him.

"Oh, that was wonderful!" Mrs. Hudson exclaimed once Sherlock finished playing violin.

Molly clapped her hands. "Yes, Sherlock," she said."You should play violin more often."

"Drinks, everyone?" John asked.

"Yes," Lestrade said.

"Thank you, John." said.

"Oh, here he comes," Sherlock said suddenly.

There were footsteps and a moment later, Mycroft Holmes showed up.

"Mycroft," John said in surprise. He didn't think that Mycroft would come. The older man didn't bother last year.

Mycroft was dressed in his usual three piece suits. This time it was black with white shirt and red tie. The ever present umbrella was in his left hand while in his right hand he held bag that was full of Christmas presents. Now, that was a surprise.

"Merry Christmas, everyone." Mycroft greeted them all.

"So good for you to come," John said.

Sherlock snorted.

And then next surprise came. From behind Mycroft, a young man in mid twenty showed up. He had dark hair, green eyes and scar which looked like bolt in his forehead. He was tall too, being in the same height as Mycroft. And next to the young man, there was a ten year old boy with bright pink hair.

"Hi, Sherlock," the young man greeted.

Sherlock waved his hand lazily as a greeting.

"Sherlock," the child however smiled in delight at the sight of Sherlock and ran to him, blabbering in... was that Latin?

John blinked. Yes, the kid was speaking in Latin with Sherlock now and the world only consulting detective was replying in the very same language.

"You must be Dr. John Watson," Harry, the young man said. "Mrs. Hudson, Miss. Hooper, Detective Inspector Lestrade, nice to meet you all. I'm Harry, Harry Potter but please just call me Harry." He introduced himself. "And that is my godson, Teddy."

The boy perked up at the mention of godson. "Hi, I'm Theodore Remus Lupin but I'm called Teddy." He said, grinning. "Nice to meet you all."

Molly squealed at the boy cuteness. "Nice to meet you too, Teddy." She said.

"Oh, so polite," Mrs. Hudson gushed out.

"Sherlock could learn a thing or two from this kid," Lestrade said, making John smiled at that.

Was this Sherlock's family? A ten year old who spoke in Latin and being so polite? Not to mention the weird name. John could really see the boy as Sherlock's family. Except for the bright pink hair. Apparently, Sherlock could read his mind because the man then said. "Harry is Mycroft's on and off boyfriend."

The reaction of this was a total silence.

"You can close your mouth anytime John. You rather resemble dying goldfish now," Sherlock broke the silence.

John closed his mouth. He didn't realize he had been gaping at Harry and Mycroft, who looked amused by their reaction.

"It's nice to see that you finally find someone, Mycroft Holmes," Mrs. Hudson said.

"Thank you, Mrs. Hudson." Mycroft replied politely. The ever proper English gentleman.

John didn't quite grasp it. Mycroft's boyfriend? Why in all the time he never ever once heard about that?

Teddy frowned at Sherlock and then said something in Latin.

Mycroft replied back in Latin and Sherlock sighed out loud. Was this some kind of secret language that Holmeses used because Harry too spoke in Latin now while the entire occupants of the flat stared in confusion.

"Oh, sorry," Harry said, finally taking a note of the other bewilderment. "Teddy is learning Latin for school now. And Mycroft and Sherlock are better in Latin than I am."

"It's alright," John said. It wasn't actually.

"And we bring something," Harry said. As if in cue, Mycroft lifted the bag in his hand and gave it to John. "It's Christmas present for everyone." He explained.

"Thank you," John replied. Oh, crap. Why didn't Mycroft tell him that he was going to be here with his boyfriend and his boyfriend's godson? He didn't have any present for Harry, Mycroft and Teddy. Dear Lord, the kid would be so disappointed.

His thought must be written in his face because Harry waved his hand and said lazily. "It's alright. As for Teddy, he had Christmas presents more than anyone could hope for."

The party went on. Harry was busy talking with Molly now with Lestrade added his opinion now and then. The young man seemed to find their job fascinating. Teddy meanwhile was busy playing with remote control, switching the various channels on telly. Mrs. Hudson was busy offering cakes, cookies and drinks for everyone. That left John with Sherlock and Mycroft. John felt headache coming already.

"So, out of the doghouse now brother?" Sherlock asked mockingly.

"Very amusing, Sherlock," Mycroft replied.

"Doghouse?" John echoed.

"Oh, yeah," Sherlock replied in glee. "Had huge row, didn't you? That's why you spent Chistmas with sulking in front of fireplace last year."

Mycroft gave his younger brother a chilling gaze.

Harry chose the moment to join them. "You aren't bickering again, are you?" he asked sternly.

"We were merely discussing Sherlock's wellbeing, dear." Mycroft replied.

Harry snorted.

John's eyebrow rose to his head. Alright, that was creepy. Even though it was said in casual way, the endearment was enough to alarm him. Looking at Harry and Mycroft who stood side by side, he didn't see any similarity between them.

"I finally met you," Harry said to him. "I've heard so many stories about you. It's nice for Sherlock to have such a loyal friend like you."

"Uhm...how long have you known each other?" he asked curiously.

"About ten years." Harry replied. "It has to do with his job." He gestured to Mycroft.

John nodded while inwardly wondered about what kind of job Harry had to cross path with Mycroft Holmes, the British Government himself. If it wasn't because of his association with Sherlock, John would never know that someone like Mycroft existed in this world. The shadow ruler behind the throne.

"And what do you do?" he asked.

"I'm law enforcement officer." Harry replied. "I read your blog too. A Study in Pink. That was your first case, wasn't it? The friendship forged in mortal peril."

Sherlock groaned and Mycroft coughed.

"I have two best friend and we were stranded in many life and death situation together many times. There couldn't be a friendship stronger than that."

That was really weird, John concluded.

"Harry! Harry!" Teddy said suddenly. "Aren't we going to the Weasleys?" the boy asked.

Harry looked at his watch. "Ah, yes. I'm afraid that we need to leave now." He said regretfully. "I have to attend my family Christmas party."

He and Teddy bid goodbye t everyone. Teddy spoke in Latin to Sherlock again. Mycroft politely bid everyone farewell.

"Well, we have to leave now. See you later."

As soon as they left, the conversation started again with Mycroft and his mysterious boyfriend as the main topic. Sherlock looked thoroughly annoyed at this.

"I can't believe Mycroft has a boyfriend," Molly exclaimed. "And how come none of us know about this?"

"He is Mycroft Holmes," Mrs. Hudson said. "If he doesn't want people to know then I doubt that people will know."

That really summed it actually. John turned to look at Sherlock. "I also don't know about this." He said. Which was understandable, every time Mycroft came to 221B Baker Street it was either to talk about case of Sherlock. Mycroft never divulge any personal information about himself.

Sherlock made an impatient sound. "As ever you see that you don't observe."

"What is t observe from Mycroft?" he asked. "His umbrella?"

"His ring, John. His ring."

"Oh!" Now, John remembered that Mycroft had ring on his right ring finger. And Harry too, had the same gold ring.

"Your observation skill really amazes me," Sherlock drawled sarcastically.

"But ring? They must be serious."

"Mummy's idea actually. Since I'm married to my job that leaves Mycroft alone. The best Mycroft could do is giving Harry his ring. Which is good so Mummy can focus on Mycroft and leave me alone."

"And who is he?" he asked because there was no way that ordinary people would know Mycroft from his job.

"The other half of the British government," was all Sherlock said.

Author's Note:

My first crossover fanfiction. Sherlock is my latest obsession now. So now I decided to write about Harry Potter and Sherlock. Mycroft Holmes is my favourite character aside of Sherlock himself.