"Sherlock!"

Such an appeal was less than futile, John knew that. After all, he had tried it often enough. Shouting at Sherlock could be as fruitless as hurling a cricket bat at a concrete wall.

"SHERLOCK!"

He had done the usual – stormed into the flat stiffly swinging his arms and gripping his fists into little balls of furious exasperation – but Sherlock was being reliably immovable.

"Not now…" he had muttered.

Today, however, was to be different. John, it seemed, had had a flame held too close to his heart.

"HE HAS GONE TOO FAR THIS TIME, SHERLOCK!"

Much too close.

Sherlock sniffed and buried his eye ostensibly further into the microscope. "Mycroft," he said. It wasn't a question.

John's fists seemed to tremble at his side. When he spoke, it was through gritted teeth, spitting every syllable as if the words themselves had offended him. "Yes, I am talking about sodding Mycroft."

There came a sigh from the microscope. "You know, John, your preoccupations are annoyingly recurrent."

"Listen to me! Sherlock!"

"John, shut up."

A pause, then…

"LISTEN TO ME! SHERLOCK, FOR ONCE CAN YOU BLOODY WELL LISTEN!"

Sherlock knew, of course, about the figurative flame and how it had licked the fibres of John's heart. He even acknowledged that this had probably been painful. It was not sympathy, however, that caused Sherlock to disentangle his mind from the intrigues of a petrie dish and to resurface, although somewhat disgruntled, into the reality that was John's love life. John's rage was rarely so fierce; rather, Sherlock was curious.

"Fine. Mycroft. What."

Suddenly weak with anger, John sank into the chair opposite. He splayed his tense hands against the table and glared into the grains in the wood, breathing heavily.

Regretting his interest, Sherlock rolled his eyes. "What? How do people like you get so worked up –"

"Shut up, Sherlock." John swallowed. "I just feel so angry." His head was bent in resignation; he had confessed it to the table.

Sherlock snorted. "Well, even the imbecile who delivers our post would be able to deduce–"

"He can do his kidnapping thing as often as he likes to me – whatever, fine –" John took a shuddered breath, "but I will not allow him to lay a finger on Mary."

Sherlock smirked. "Ah, yes."

"I'm sorry?"

The smirk dissolved slightly. It was irritating, always having to explain himself. "Well it's obvious," Sherlock said, waving his hand vaguely: "Your shirt."

Clenching his fists again, John muttered: "What? What's 'obvious', Sherlock? 'Cause I am really not in the mood for your arrogant 'deductions' right now. Mycroft has abducted Mary! You have to tell him to lay off!" He swallowed, panting slightly. Sherlock, he noticed, had returned his attentions to the petrie dish. "And it has nothing to do with my shirt," he added under his breath.

"Yes, yes, boring, boring. I know." Sherlock focused the lens. "And it does."

Once again, John felt his intellect grapple helplessly at the precipice of Sherlock's mind. "I don't follow," he muttered reluctantly.

Sherlock sighed, but it was superficial – his insides were squirming into a sly grin. "Your shirt. The collar has a dark smudge – possibly mascara – and you have an extra button undone – signs of intimacy that has been, shall we say, interrupted. You've been with a woman – that's obvious, how else does the macara get there – and you wouldn't be seen in public with a button out of place, except that you were interrupted, which means you've been upset, distracted and ran here without stopping to dignify yourself."

John opened his mouth to speak, but closed it quickly as Sherlock continued.

"How do I know it was Mary? One, you reek of girl – that nauseating peachy scent she seems to audaciously excrete everywhere – and two, you only become as loud and irritating as that when Mary's involved."

John picked absently at a knot in the wood of the table. "How did you know it was Mycroft?" he asked meekly.

"He texted me."

"Oh."

"Which isn't cheating –"

"I didn't say it was."

"– because he was only being irritating and asking for the whereabouts of my 'pocket-pal'. Which is you."

"Right."

There followed a silence, which Sherlock misinterpreted as cordial and proceded to turn fiddle with a specimen beneath a glass slide.

John coughed. "Her perfume isn't nauseating," he grumbled and, when Sherlock ignored him, added, "Are you going to speak to Mycroft?"

Before Sherlock could contemplate a reply, the door into the hallway burst open and in its frame appeared Mrs Hudson.

"Boys!" she gasped – for she had run up the staircase – "Was that more arguing I heard earlier?" She bustled into the living room, smiling fondly at the mess. "You haven't been very nice to each other recently, have you. What was –?"

"John doesn't want my brother talking to his girlfriend," Sherlock said dismissively.

"Oh, John" – Mrs Hudson's honeyed concern made John curl further over the table-top – "I don't think Sherlock's brother will want to steal your girlfriend –"

John winced, his anger having dissipated to a painful agitation. "Well, that's just it: he has stolen her," he muttered bitterly.

Mrs Hudson squeaked. "Sherlock? Is this true? Your brother stealing John's girlfriend?"

"Ah, Mrs Hudson, you have well and truly missed the point," Sherlock spoke into the lens. "Besides, while John's women seem to be an acquired taste, my brother, I think, hasn't acquired a taste for women at all."

Giggling, Mrs Hudson began clearing dirty plates from the table, saying as she did so, "Oh, Sherlock, you and your funny little riddles."

John grasped his head in his hands and groaned. They were equally as useless and irritating as the other. Maybe this was how it felt to live inside Sherlock's impatient, embittered mind. Sherlock fiddled with the microscope slide; Mrs Hudson knocked their already chipped crockery about in the kitchen sink. John groaned again: "Quite frankly, I just want Mycroft to piss off."

"You're very protective, aren't you John, dear? It's very sweet," Mrs Hudson giggled form the kitchen.

"And yet," muttered Sherlock, "My brother is just a sexless, inquisitive rodent; really nothing to bother about."

John's shoulders shook, the frustration mounting into anger once more. "Are you even listening, Sherlock? Or are you attempting to strike up a relationship with that virus you're breeding."

"The virus is certainly less parasitic than the way your concerns seem to eat away at my sanity."

"You're not sane, Sherlock," John said coldly.

"Sociopathy is not necessarily insanity by all schools of psychological thought."

"Whatever –"

"And yes, I was listening and no, I will not be speaking to Mycroft, as is a general rule. He's just being obsessive about my safety; probably checking that your girlfriend isn't the Mafia."

"Of course she's not –"

"It's a wise precaution, John. Although I don't appreciate him doing it for my sake, I must admit the value in the practice of screening."

"Well, I'll appreciate it –" John's voice grew louder and his cheeks reddened, "– I'll appreciate it if he doesn't 'screen' Mary again."

"You tell him that."

"Maybe I WILL!"

"BOYS!" Two voices cried in unison: one squeaked from the kitchen sink, the other reprimanding from the open doorway.

"Mary," John breathed.