Sherlock had survived surgery.

That was all that John knew, all that he cared about, all that he could hear.

'John?' James Macpherson was saying.

'Sorry, sorry,' John said, focusing his gaze at the picture of the lake scene on the far wall of the ITU relatives room, which he had been staring at for half the night, trying to ground himself. 'I'm just - thank you James. You did a good job.'

'He's not out of he woods yet,' James warned him. 'The next twenty four hours will be crucial. If the bleeding restarts, or if he goes into failure, then he's in trouble. But he's relatively young and fit, so he should have enough reserve to get through.'

John thought about finding Sherlock coming down from his high in the crack den that morning. He hadn't looked particularly fit then. Should he tell James? Sherlock had said that it was for a case, after all, but the toxicology screen that Molly had done had been positive. He had used drugs, and not in the cleanest of environments either. He had potentially put himself at risk of all kinds of infection - not to mention the risks of sharing needles. But he wouldn't have done that would he? He wouldn't have been that stupid. Not even for a case.

'Is there something that I need to know?' James asked, reading the conflict on John's face. For a man who had been operating for most of the night, he was still remarkably alert and switched on.

'In confidentiality?' John asked.

'Of course.'

'And not to go in his notes?'

'Just tell me, John. The smallest thing could make a difference at this point.'

'He's been using drugs.' John's words came out in a tumble. 'He said it was for a case, but I'm not so sure. He had a problem before - years ago. I have no idea how deep it's got this time.'

'Do you know what?'

'Heroin, I think, from how he was this morning. I'm not sure what else. I think he used cocaine before too though, among other things.'

'Has he been using it intravenously?'

'I think so.'

'Then we need to do a toxicology screen, and check him for blood borne viruses - HIV, hepatitis. It's important that we know John, you know that.'

'On the record?' John asked.

'The blood-borne virus screen is routine for the majority of ITU patients anyway - in case we need to haemofilter them, so it's easy to get that done. If the drug screen comes back as positive, then it should be in his notes, so that everyone who is treating him is aware. If he has been abusing opiates then it will have an impact on the amount of analgesia that he needs here to keep him comfortable. Besides, we don't know that Sherlock would object to being tested. We have to act in his best interests at the moment, until he can express an opinion.'

'I've got power of attorney,' John said suddenly.

'What?'

'I've got Long Acting Power of Attorney for him. He did it years ago - so I could stop Mycroft from interfering if he got incapacitated. I'd forgotten.'

'Do you have the form?'

'There's a copy at home somewhere, and one filed with his solicitor. I can call them.'

'Get them to fax it over will you? That means that you can make decisions for him. Does it specify medical decisions and life-saving treatment too?'

'Of course. Sherlock was nothing if not prepared, no matter how chaotic his life might have appeared to outsiders.'

'So can we test him.'

'Absolutely,' John said, realising that this was exactly what Sherlock, who had after all wanted Magnussen to believe that he was a drug addict, would want. It was all about the case, always about the case, and if he ever recovered enough to get back to it, then he would extract some degree of amusement in knowing that the work had continued even while he was unconscious. He considered telling James that Sherlock had already been tested, less than twenty four hours ago and had tested positive - although for what substance, Molly hadn't said. But James would find out soon enough.

'James - I'm sorry I didn't tell you. Before.'

'Before I had my hands up to my wrists in his thoracic cavity?' John winced at the imagery that evoked.

'Don't worry, John. There wasn't exactly a lot of time to play with before we took him upstairs. It's a risk that we always take. Gun shot wound victims round here don't tend to come from the higher stratus of society, if you know what I mean.'

'Gang violence?' John asked interested.

'Sometimes. Or disputes about drugs, both are common. We always try not to judge, of course, but it's refreshing to operate on someone in these circumstances when you know that their survival will be a force for good. Most of the time you're not so sure.'

John reached over and shook James' hand. 'Thank you, James,' he said, with feeling.

'I know how much he means to you, John,' James said. 'I would have done the same for any patient, but rarely have I operated on anyone when I felt that the stakes were so high.'

'Was it close?' John asked.

'He gave us a few hairy moments. There was a lot of blood in both the right side of the chest and the mediastinum. Opening up the pericardium always carries a risk in a patient with a known tamponade. Fortunately we had bypass standing by for when his pressure dropped.'

'Did he arrest?' John asked, back in doctor mode now. Wanting to know, needing to know the details of the surgery that he hadn't been allowed to witness.

'Technically, yes, but it was less than two minutes before we had him on bypass. He shouldn't suffer any lasting neurological damage. Whether he has any long term sequelae from the prolonged period of hypotension is another question. His brain must have been deprived of oxygen for a significant amount of time.'

'He wouldn't handle that well,' John said.

'One step at a time. Let's get him through the next twenty four hours and off ITU first, then we can deal with the rest.'

'So where was the bleeding coming from in the end?'

'The bullet had gone slightly tangentially in at the fifth intercostal space, as you saw. It hit the right middle lobe of the lung, went into the pericardium, just grazed the right ventricle without entering the chamber, but then penetrated the IVC; that was where most of the bleeding was coming from. It ended up lodged in the transverse process of his vertebra posteriorly, Another couple of centimetres laterally and it would have hit his spinal cord, and then he would have been in trouble.'

'Have the police got the bullet for ballistics?' John asked.

'Yes, and I've given them the brief version of his injuries. I said I'd go back and talk to them in more detail once I'd let you know what the situation was.'

'Greg Lestrade's a good friend of mine - and Sherlock's,' John said. 'He's leading the investigation. If anyone can find the shooter, he can.'

'I'll give him as much information as I can,' James said. 'And now here's something interesting for you. I think the shooter was left handed.'

John smirked slightly, despite everything. 'Sherlock rubbing off on you?'

'I've seen a few gun shot wounds. Been to court for a fair few, too. You pick up pointers from the forensic reports. Few gunshot wounds have an entirely straight trajectory, and people tend to shoot slightly laterally. The entry wound was on the right side of his chest, then angled maybe five degrees medially. For a right handed shooter to do that, they would have had to be standing to Sherlock's right and then the angle would have been greater. It's just a hunch.'

John failed to conceal his surprise. 'Well make sure you tell Lestrade about your hunch,' he said. 'It sounds like a good one. And if you're right, it will rule out ninety percent of the population, so that's a good start.'

'I will do.'

'So when can I see Sherlock?'

'They're just moving him onto the unit now. Give them ten minutes or so to get him transferred across and do handover, and you can go and sit with him. I presume that I don't need to warn you...'

'That he'll look like crap? No, that's fine. The fact that he's alive will do me. Tubes everywhere, I presume?'

'He's got a chest drain and a pericardial drain as well as all the usual lines. We'll try and get the pericardial drain out in a day or two - it's mainly there to help us watch for rebleeding. We'll keep him sedated and tubed for twenty four hours at least; optimise his ventilation and cardiac function, correct the acidosis, make sure there's no further bleeding, then if all goes well they'll do a sedation hold tomorrow and see how he does.'

'Thank you, James,' John said, shaking his hand again. 'So, do you get to go home and sleep now?'

James grinned at him. 'What do you think? No, I've got a ward round in -' he looked at his watch, 'Two and a half hours, and then clinic all morning. I'll go and try to get my head down in my office for a couple of hours or so, I think, and then grab a shower in the theatres changing room before starting my day. Still, it was a nice bit of surgery. Makes the sleep-deprivation worth while.'

'You're making me glad I opted for General Practice,' John said.

'More sleep, less glory,' James said. 'I'll come back and see Sherlock after my clinic. In the meantime, they know where I am, if they need me.'

John spent the next ten minutes staring at that picture of the lake again, and turning his phone over and over in his hands. He wondered what Mycroft Holmes could be up to that would justify him leaving John to keep his vigil alone, and wondered if he should phone Mary. Half past five. She'd be getting up in an hour and a half to go to work. Better to leave it until then. If all was going well, he might just leave Sherlock to the care of the ITU staff and go home and try to get some sleep. Alive. He was alive. That was what mattered.

A quiet knock on the door made him jump, and heralded the arrival in the room of two men in scrubs. One introduced himself as the ITU consultant, the other as the ITU charge nurse. The arrival of medical staff in twos always rang alarm bells with John. It generally meant bad news, but not it seemed on that occasion. Sherlock was critically ill, but he was alive. The next twenty four hours would be crucial, he knew this. The situation could deteriorate. Sherlock was currently being kept alive by a cocktail of inotropes, anaesthetic agents, blood, clotting factors, and various pieces of extremely complex machinery, but none of that mattered. He was alive. And if he could survive jumping over a hundred feet off a roof to certain death, then he could survive this.

Not even seeing Sherlock lying, pale and unresponsive, surrounded by a myriad of beeping and clicking machines, with fluids being poured into him and drained out of him, could take away the overwhelming feeling of relief. John sat with Sherlock for a while, held his hand and talked to him in a way that he never would have been able to had he been awake. It reminded him oddly of his conversations that he had had with Sherlock at his presumed grave, and he remembered him saying, 'I heard you.' He hoped that Sherlock could hear him now, as he told him that they needed him to wake up and get well. That Lestrade needed his help to solve the case. That they needed him to tell them who had shot him, and that Magnussen was still out there, and needed to be stopped. That the game was still on, and waiting for him.

Whether Sherlock heard him or not, he had no idea, but the fact that he could be here, talking to him, was enough. And leaving a case unsolved just wasn't his style. John was banking on that.

This chapter is deliberately medically accurate, rather than entirely accurate to the screen version. Because unfortunately there's no way that Sherlock could have survived a gunshot wound in that place, with a cardiac arrest, without having bilateral thoracostomies, and that very neat little scar that we saw on screen just wouldn't do it.

I'm not an intensivist or a cardiothoracic surgeon, so if anyone does spot any inaccuracies please do PM me and let me know. I'm hoping I've made it as realistic as I can. As ever, thank you all for reading x