Mycroft phoned and Sherlock cut him off. John rolled his eyes, but said nothing. Mycroft phoned John instead, but on Sherlock's instruction, John let it ring off.

"Why, what have you done?" John inquired, once the ringing had stopped and he'd returned to his typing.

Sherlock didn't look up from his chemistry set.
"Nothing, so he wants me for a case. It must be related to his work because he'd just come here otherwise, something is keeping him at Whitehall. If it was delicate enough to be potentially interesting he'd just send in the cavalry as with the Adler case-"

John smirked at the memory of being picked up by a helicopter. Then again, as he remembered it, he had been at a crime scene, talking to a laptop because Sherlock couldn't be bothered to leave the flat to do his own job. Mycroft hadn't been the only Holmes brother showing an imperial flare that day.

"- In conclusion, something incredibly dull and political has disrupted Mycroft's day and rather than leave his office himself, he wants me to do it for him."

"You'd rather not then I take it?" John teased, amused by the look of utter contempt on Sherlock's face.

"Not while avoiding him is so much more entertaining." Sherlock replied dryly, as his phone rang again. Sherlock didn't bother to cut him off that time, just letting it ring. His growing smirk told John he was imagining how annoyed Mycroft would be getting.

There was a five minute pause, in which the sound of fizzing from Sherlock's chemical mess in the kitchen and clacking from John's laptop in the living room, were the only sounds to be heard in the flat. A buzzing sound from John's pocket interrupted and John giggled. Mycroft had resorted to Sherlock's preferred method of communication, but still thought John the less likely to ignore a text.

Well, John was indeed, less likely to ignore it to the extent of not reading it, as Sherlock's frown indicated he would have done. That he would read it, didn't make him any more likely to respond to the barely veiled command it was likely to involve.

It took a minute for the words on his screen to sink in as a whole, for his brain to remove the sarcasm and frankly terrifying stoicism of the British Government and for John to feel like he'd swallowed an ice cube.
"Oh my…Fuck. Sherlock, call Mycroft." John breathed, staring at his phone in disbelief.

Sherlock looked up, surprised by the tone of John's voice, but not by his order. Mycroft contacted John when Sherlock was being difficult, for a reason. John's soldier's heart was outweighed only by his loyalty. While John would do nothing for Mycroft that involved any form of betrayal to Sherlock, Mycroft still knew how to marshal the captain. What Sherlock couldn't quite explain was why John sounded so panicked. Less than friendly thoughts directed at his brother and what on earth he'd said, spun through Sherlock's mind.

… "John, what-"

"NOW, SHERLOCK!"

Sherlock's hand was on his phone almost before John had stopped shouting. Apparently it wasn't just soldiers who couldn't help yielding to an authoritative rank of order.

Sherlock's call was answered very quickly.
"Mycroft, what's…what? What? Mycroft! …Yes, hello, who is this? …Yes I am. What…hello? What the hell?!"

Sherlock turned a mystified, rather alarmed looking glare on John, who ignored his palpable anger in favour of grilling him for information.

"What did he say? Who did you speak to?"

Sherlock took an obvious, but steadying breath, ridding himself of frustration which clouded his ability to reach answers quickly, especially when it was John he was trying to get them out of.
"He said he's in hospital and could I talk to a nurse for him. A nurse then said not to worry but asked am I Mycroft's next of kin and could I make sure I was contactable in case of emergency." He answered, managing to sound almost entirely calm.

John stood up and crossed the living room floor to the kitchen, plonking his phone down next to his flatmate.

Sherlock glanced down at the screen, open on Mycroft's text. As he grabbed his coat and scarf and pelted from his flat, with John at his heels, it was hard to tell whether Sherlock was more furious at, worried about or amused by his brother.

As their taxi halted outside the hospital and Sherlock paused for long enough to pay the driver, John made a quiet comment Sherlock felt he couldn't really argue with at that moment.

"Sherlock, can I suggest you don't ignore phone calls from your brother, ever again?"

Sherlock nodded grimly, handing John back the phone he'd accidentally forgotten to give back in their hasty exit. In spite of their location, John smirked at screen, still displaying the elder Holmes' extraordinary summons.

'Hello John, there was a small incident at the office today, could you please ask Sherlock to phone me back and confirm for the hospital he is my next of kin, so the nice doctor can knock me out to remove the not so nice bullet from my arm. Kind Regards, MH.'