Detective Inspector Gregory Lestrade took a deep breath and tried to prepare himself for what he tried to convince himself was not the biggest challenge of his career.

"All right, Sherlock, listen to me. I have a theory. I've been talking to John for a couple of months now, and he's only been getting more depressed-"

"Well, then you're obviously-"

"No! Listen to me. You know I'm good at talking to people and John's my friend but I'm not getting through to him and my theory is that is because it's me talking to him and not you."

"Why should that matter?" asked Sherlock, confused, and Greg Lestrade was sure that this was one conversation he never wanted to have. As always, genius Sherlock Holmes may be but emotional matters always seemed to elude him.

"Because you're his best friend for whatever unknown reason! How to explain this? Um, say you were at an all time low, say you, I don't know, lost the ability to think, became normal and the only person who would talk to you properly was me. I would say Mycroft since he's the only one who understands your brain but you'd just kill him. Anyway, how would you feel if you were at your very worst and John just backed off, didn't try to help?"

There was a pause as Sherlock tried to process everything Greg had said and Greg thought it was the longest he had ever seen Sherlock take to process something. He was probably having to create a new room in that 'Mind Palace' of his.

"But that's different," Sherlock said, "I was doing what was best for John, I don't understand emotions like these, but John's the only one who understands my brain and me, so it wouldn't make sense for him to back off."

"I know! But John doesn't know that. All he is seeing is his best friend abandoning him when he's at his lowest. You need to talk to him, Sherlock."

"OK. I think I see that. But I can't start having a … heart to heart with John. I don't know how."

And so DI Gregory Lestrade was faced with what he could not now deny was the biggest challenge of his career: teaching Sherlock how to talk to John sensitively. Even harder when he wasn't sure what Sherlock needed to say himself. All he knew was that he was sure, for whatever reason, consciously or subconsciously, John wanted Sherlock to be the one to fix him and Greg was determined that even if he couldn't cure John himself, he could help Sherlock do so.

They got themselves firmly ensconced in Greg's flat and Greg procured the first requirement: coffee, black, two sugars for Sherlock. He was tempted to go for something stronger but he needed his brain as sharp as possible.

"OK. Rule One: John is not an experiment, a case or an object to be fixed; he's your friend. Do you understand the very vital difference?"

"But he does need to be fixed!"

"OK, true, I guess. But if you go at it from that angle he's going to think he's going to think he's no different in your mind than the severed head in your fridge. Just another experiment."

"The head's been gone for months now, how unobservant can you be?"

"That's not the point! It was an example. He needs to know he's important."

"But he does know he's important. Obviously he's important."

Greg felt the days stretch ahead of him.

John knew Sherlock and Greg had been talking a lot, about something very important. They were always somewhere else, always talking. Hurried whispers and glancing, darting gazes. Did they think he didn't notice? Or did they know and just not care.

It was a new case, no doubt. A case. It must have been a good one, to keep Sherlock's interest for this long. An eight at least. Possibly even a nine or a ten, judging from the way Sherlock was acting. John had lost count of the nicotine patches Sherlock had got through. They hadn't even told him about this new case. An eight and they hadn't even included him.

John had thought he would be upset, instead he only felt numb. A complete and utter lack of energy. He just sat and stared at nothing. He had known it would come to this, eventually.

Mycroft had been watching everything, of course. He remembered the time that John had joked that Mycroft was Big Brother, literally and metaphorically, back before when John still made jokes. They had an odd relationship, but it was warm in it's own way. But tonight was the night. Lestrade had been coaching his little brother and tonight Sherlock would talk to John. Tonight he would play the role he was possibly least suited for – therapist, but for some reason, most definitely unknown to John himself (Mycroft was quite sure John hadn't realised his feelings yet, nor had Sherlock, for that matter). Tonight Sherlock would either ruin everything forever or begin the road to recovery.

Mycroft was not a religious or superstitious man, but he knew Sherlock's skills and at precisely 8.00pm, when he knew Sherlock was arriving at 221B, Mycroft sat in his office and hoped.

Sherlock hadn't felt this nervous entering 221B since he had returned from the dead. It was ridiculous; he knew what he had to do. But still, this could be the make or break and he could stand to loose John.

John was sitting in his usual armchair. He didn't even look up as he entered the room. Sherlock walked and collapsed into his armchair.

"Hello John."

Was this is? Was he finally being thrown out of 221B? Of his home? Sherlock's whole manner since entering the flat had been strange, anxious, and almost nervous. Sherlock never got nervous. He didn't seem to be able to look at John for more than a second at a time. Unable to stand the tension John exploded, his anger a shield.

"All right," he said bitterly, "if you want me to go, I'll go. You don't need to draw it out."

"What?" replied Sherlock, seemingly perplexed.

"Well you obviously want to tell me something and you're practically shaking with nerves, so just spit it out, damn you."

Usually Sherlock was never fazed when John shouted, but this time Sherlock was silent for a long time. John even feared he'd made things worse, but Sherlock's face gradually changed to what John had privately called his 'deducing expression' and then the familiar look of dawning realisation and triumph.

"I think I see what the problem is."