AN /: No plot to find, it's just something random that I came up with during a heatwave thanks to a particularly amusing internet meme, because, let's face it, it would be awesome.

O.o.O.o.O

The letter comes in the mail without warning but with a definite sense of nostalgia about it. John finds it sitting next to the apartment door as he arrives home from the surgery, a thick letter encased in a crisp white envelope, his name and address printed neatly onto the front in a block script that he doesn't recognise. He picks it up and flips it over, walking into the flat and sinking down into his armchair. Sherlock looks over at him curiously, his legs dangling off the arm of the couch, his mobile sitting on his chest and moving slowly up and down as he breathes.

"You never get personal letters." He says.

"How do you know it's personal,' John says as he rips the top open. "It could be a bill."

"You were surprised to see it,' Sherlock says with a role of his eyes,' you're only ever irritated when you receive bills. That and the address is handwritten."

John makes a non-committal but appreciative noise at Sherlock's brilliance as he pulls four sheets of paper out of the envelope, all covered in a very familiar handwriting. He can't help but smile now. The letter is from a very old friend, someone he hasn't seen in ages, and soon he is engrossed in the letter, laughing occasionally and sighing wistfully every now and then. Sherlock returns his attention to the roof, but as John laughs again he becomes curious.

He has no idea who the letter is from. It can't be family, as Harry will only contact him via his blog and an occasional text. It can't be his parents because they mostly email John, and not very often at that. It is most likely a friend, a very close one at that, and one that John has not heard from in a while judging by the sheer amount of paper, which is also double sided.

"Who was it?" Sherlock asks as John puts down the letter, a smile on his face.

"Just an old friend..." John says.

"I know that, but who was it?" Sherlock insists. John frowns, reluctant to divulge the answer. Sherlock will be sure to laugh if he does.

"It's no-one Sherlock, forget about it." John says, but as soon as he finishes his sentence he knows he has made a very grave mistake. Sherlock moves with a surprising amount of speed and launches himself from the couch, reaching over to grab the letters, his phone falling to the floor with a solid thud. With an impressive reaction time John lifts the letters above his head before Sherlock can snatch them away and Sherlock only succeeds in finding himself draped across John's lap.

"We should stop meeting like this,' John says, fighting back a laugh, and Sherlock glares at him. He is pushed lightly off Johns lap as the older man stands and he crosses his arms, watching the letters in John's hand. He hadn't even been able to get a good look at them during his dive, but that won't stop him from getting them eventually.

"It can't be your parents,' Sherlock says, following John into the kitchen. "Your parents don't write letters, they barely even call." John makes a noise in the back of his throat and ignores Sherlock completely. He tucks the letters under his jumper and inside his singlet, the safest place he can think of at the present moment.

"It's not Harry and it's not any other family members,' Sherlock continues, literally one step behind him as he wanders about gathering ingredients for something that could at a stretch be called dinner,' it's not Mike, it's not anyone that you communicate with regularly, they would email you or contact you via your blog. It is also someone that you are deeply attached to, considering your reaction to discovering the identity of the writer. An old girlfriend perhaps, judging by the faint blush on your face?"

"Definitely not." John says, pulling a face.

"Well if it's not an old partner and it's not from friend or family... you don't have any particularly endearing enemies, do you?"

"Normal people don't have enemies." John reminds him, and in the time it takes for him to turn his head Sherlock sticks a hand up under John's singlet and grabs the letters. He is too shocked to stop him, and his reaction is about three seconds too late.

"Sherlock! You can't just- you can't go around and- and- you can't just stick your hand up people's shirts!" John stutters.

"You and your silly social conventions!" Sherlock says as he sits back on the couch, and now that John thinks about it he really shouldn't have been surprised at a breach of personal space coming from Sherlock 'defies social etiquette and personal space' Holmes. But Sherlock does have his letter now. Damn.

As mortified as he is that Sherlock now has his very private letter, John can't help but watch Sherlock's face. First there is the smug look, the one that spreads itself over Sherlock's face far too often. Then there is the inevitable bafflement as he begins to read the letter, his smug grin being replaced ever so slowly with a long frown. Finally there is complete confusion as he realises who the letter is from. Sherlock blinks a few times when he is finished, staring blankly at the pages.

"It's from your moustache." Sherlock says flatly.

"Yep."

"Not just a nickname for someone, presumably your actual moustache."

"The one and only."

"And your moustache is fighting terrorism in Afghanistan, aiding people who have been rendered homeless after mass flooding in Australia, and personally taking on the Talliban. This must be a joke. Did Mycroft put you up to this?"

"No, as hard as it is to believe, it really is from my actual moustache. After I was shot it told me that it didn't want to give up the fight just yet, hopped off my face and enlisted itself. It writes back every now and then, thinks highly of you, and wishes us all the best in our escapades chasing criminals around London. I have also never had to shave since."

Sherlock blinks again, his expression unreadable. "I've always wondered why you never shaved,' he mutters, and John breaks into fits of laughter.

END