AN - Makes most sense if read as established Johnlock but doesn't have to be unless you ship them. Could also be read as AU Reichenbach but again, doesn't have to. Hope you like it, if not please tell me where I went wrong (the wittier (is that a word? Well it is now) the review the better in my opinion). This fic is also on AO3 under the same name.
Disclaimer: All rights to Sherlock go to Mark Gatiss, Steven Moffat and the BBC (much to my annoyance).
"Where would you be going?"
"Not important."
Lestrade looked incredulous. "It is bloody important, Sherlock. I mean would you be able to phone him or whatever?"
"Unlikely." Sherlock said calmly.
"And your brother thinks no-one else can do it?"
"If Mycroft thought someone else could do it then he would have asked them."
"And how long is it for again?"
"Not important!"
Lestrade sighed into his coffee, how did one give advice to Sherlock Holmes?
"I mean why are you going? You never normally do what Mycroft tells you."
"So?"
"Well if you leave then people are going to talk, and you've got a good thing going here. So unless there's something going on here that you, for whatever reason, don't want to talk about I don't understand why you want to leave."
Sherlock smiled at that.
"Not completely terrible." He said. "So you think I should stay?"
"Unless there's something you're not telling me then yeah."
"What's the job exactly?"
"Undercover."
"Any chance you could tell me what kind of undercover?" Molly chanced her luck, thoroughly expecting the eye roll she got in return.
"Not in this country."
"And there's no chance John could go with you?"
"No."
Molly thought for a moment.
"Well, I mean if you're not happy then… well I guess you have to do what's best for you." She said at last.
"Really?" Sherlock asked.
"Really." Molly replied.
"Well what's wrong love?" Mrs Hudson asked, setting a cup of tea down.
"Nothing, Mrs Hudson."
"Why then, hmm?"
"…I don't know." Sherlock looked at the ground, as though embarrassed to admit it.
"Has he made you unhappy?"
"No…" He paused, unsure how to proceed. "He's made me very happy."
"But you're still thinking about leaving?"
"Yes."
"And do you think it's John that's the problem."
"I don't think so."
"Then what is?"
"I don't know." Sherlock said for the second time that evening. "Do you think I should stay or go?"
"Sherlock love, if you think that leaving will make you happier then of course you should go."
"Would you look after John if I did?"
"Of course I would dear."
"So you're considering walking away from a relationship which has brought you great happiness and which has, apparently, nothing stopping it from continuing to do so for no reason other than… what exactly?"
"I didn't come to be insulted Mycroft." Sherlock snapped.
"You truly want to leave?"
"I don't know! All day people have been asking me if that's what I want and I just don't know!"
Mycroft's smug smile turned into a frown, he had never heard Sherlock admit he didn't know before, nor had he seen his mood change so quickly.
"Sherlock… you must know that this is no more my area than it is yours."
"I know."
Mycroft sighed. "On paper it's the stupidest idea I have ever heard, and I would say you're intelligence has lowered to that of a goldfish by even thinking about it. But, as I say, I am inept at matters of the heart."
"Which means?"
Mycroft put a hand on his little brother's shoulder. "Which means I don't know either. I would say stay, see if things will change, but the choice must be yours."
Sherlock looked down and swallowed. It was a few minutes before Mycroft noticed the tears creeping down his baby brother's cheeks.
"Sherlock?" He said, his frown deepening.
Sherlock jumped, as though he had forgotten Mycroft was there. His hand came up to wipe away the tears. Wordlessly Mycroft pulled him into a hug.
"I don't know what to do." Sherlock stammered. "I love him, but I don't want to stay and I don't know why."
Mycroft continued to hold him there gently. "I can't choose for you Sherlock, but if you don't want to stay then you should go." At last Sherlock pulled away and stood up hastily.
"I should go." He said, pulling on his coat and scarf.
"Sherlock wait-" Mycroft started but Sherlock cut him off.
"I'll text you when I decide."
"I'll get a car for you to-"
"Don't bother, I'll get a cab."
"Sherlock!"
John collapsed on the bed that had, up until a week ago, been Sherlock's. It had been a long day, the funeral had been busier than expected and the days running up to it filled with people filling the blog with messages of 'sympathy' and the odd few asking for interviews. As he lent back to heel off his shoes the crackle something beneath the sheets distracted him. Standing up and taking it out he saw it was an envelope. 'John' it said on the front. He tore it open, unsure if he wanted to read what was inside.
Dear John it read
I'm sorry, savour that sentence because I won't say it again. But I am sorry, very sorry. I hope you can forgive me, it's an addiction. The only way to clean myself of all my faults. Everyone thought I didn't care, that I was heartless, and it was almost easier to let them think that to keep them at arm's reach. You saw through some of it, through the cold comments and the wanting to be alone. But you couldn't see through the attitude, the armour that kept anyone from seeing me. I wish I had had the bravery to confess to you, but I didn't and I'm sorry for whatever sadness this solution may cause you. I wish that I was a machine, that I could let everyone's loathing slide off me, but I'm not and I can only thank you for being my friend. Look after yourself and the others.
Sherlock