'Now talk and sort it out. Do it quickly.'

Sherlock made it sound so easy. John stared at Mary, wanting to say so many things to her, but somehow, the thoughts just refused to form themselves into words What he felt was too complex, too intense to verbalise. He wanted more than anything to just walk out of that door and never see her again. But there was a baby involved - his baby. His child was being carried by the woman who had lied to him, time and again about who and what she was. And worse, it was being carried by the woman who had tried to shoot Sherlock and had then sat by his side at Sherlock's hospital bed in intensive care, never once showing anything other than compassion and concern. How could she have lied to him so convincingly? And, more to the point, how could he have allowed himself to be deceived so completely?

And so John stared at Mary, and Mary stared at John and neither of them spoke. In the end it was Sherlock who broke the silence. 'Baker Street,' he said. 'Now.'

There was a cab waiting outside, of course there was. The same black cab that had brought John to Leinster Gardens in the first place.

'I'll walk,' he said, turning away. No way in hell was he going to sit pleasantly beside Mary for the journey back to Baker Street as if nothing had happened. And the cab, like most London black cabs, had only an empty space for luggage beside the driver where the front passenger seat should be, so not even that option was available to him.

'John -' came Sherlock's voice as John started to head for the main road, and he hoped another cab. For all his bravado it was a long walk back to Baker Street. He kept walking, not realising that Sherlock had caught him up and was walking beside him until he felt a hand on his arm.

'John, you promised that you would trust me.'

'I can't, Sherlock. I can't sit in a cab beside her without - without,' he shook his head and looked at the ground, hands formed into fists. Without what? Without thumping his pregnant wife? Would he? Could he? Was that what he was really afraid of?

'Then don't sit beside her,' Sherlock answered. And then when John failed to move, squeezed his arm for added emphasis. 'John, please. This is important. We don't have much time.'

John shook his head. 'Of all the things that you've asked me to do for you..'

'I know. Now do this.'

John sighed, and pulling his arm away from Sherlock's grip, walked back towards the cab, heading for the kerb-side door, ignoring Mary, illuminated by the interior light of the cab, watching him as he approached. He wrenched open the door, and ignoring the empty seat beside his wife, instead sat down on the jump seat, leaving Sherlock to slide into the seat next to Mary.

He kept his gaze focused out of the window, avoiding looking at the others. He would travel back to Baker Street with them if he must, but he was damned if he was going to have this conversation in a cab. They travelled in silence, the only noise the hum of the diesel engine, and concerningly, Sherlock's rapid breathing, the events of the evenings obviously taking their toll. But when John looked up to check on him, Sherlock just shook his head at him in his old code on a case for 'Leave it,' and John resumed his focus on the world outside his window, forcing his anger down to a controllable level.

There was a technique that he'd learnt from Ella during his months of therapy, when he had freshly returned from Afghanistan and anger and grief had threatened to consume him. It was a technique of dissociation, of forcing himself to watch his thoughts from a distance rather than trying to suppress them, while remaining emotionally disconnected. A way of allowing all the thoughts racing through his head to go where they would, rather than suppressing them until they erupted into violence.

He had got into a few fights those first few weeks after he had been released from hospital, before he had met Sherlock, while he was still trying to work out what the hell he was going to do with his life. He wasn't proud of it, but Jesus it had felt good at the time. Wiping the smug smiles off the faces of the little pricks who had thought that a short bloke with a crutch out on his own was an easy target for their knew he was in trouble when he started walking the street so at night looking for groups of teenagers and smug twenty-somethings that he could teach a lesson to. Like some strange crutch-carrying vigilante. That was when he'd dug out the card that had been given by the psychologists at Headley Court, at the end of his stay on the military rehab unit there, and had finally phoned Ella for an appointment.

'You need to learn to disconnect from events around you when you're struggling to cope with your emotions,' she had said to him. 'Take a physical and a mental step back from the situation, and then just allow your mind to wander wherever it wants. Don't try to analyse anything, don't try to direct where they are going, just sit back and watch and try to remain as detached as possible, try to avoid putting any kind of emotional significance onto them. Just - watch. The problems come when you try to suppress things, This is a way of enabling your mind to defragment itself if you like. Eventually your thoughts will start to arrange themselves into rational cognitive sets, and that is something we can work on here too.' And so they had, and over time the anger and the despair had hit him less often, but even now at times of stress, John found himself reverting to the technique. Disconnecting to remain in control. An odd theory, but an effective one.

Once the initial anger had faded, he found it oddly soothing, just allowing thoughts and memories to flood through his mind. It was a little like meditation without the need to clear your mind or push thoughts away. John had always been dreadful at meditation - his mind was too busy a place. He had gone out with a girl who was a yoga-nut for a while, when he was a house officer, fresh out of medical school. She had dragged him to yoga classes with her where he was nearly always the token man, but while the exercise part of it and the breathing he had found calming, it was the relaxation part that he had been unable to cope with.

Even with every cognitive trick that he had learnt fully deployed, they arrived at Baker Street long before John was ready to face what must come next. He got out of the cab first, and threw a twenty pound note at the cabby without even waiting to hear the fare, then opened the door with his key and set off up the stairs. Behind him he was vaguely aware of the softer steps of Mary, and behind her, he knew, was Sherlock. He could hear his breathing as he started up the stairs. It sounded laboured - Christ, Sherlock. How the hell was he was coping physically with all of this? He'd just come out of intensive care, for heaven's sake. He'd had his chest cracked open and was recovering from open heart surgery. But John found himself pushing his medical concern to the side as soon as he walked through the door to 221B.

Sherlock had planned this. He knew what he was doing and he was doing it for a reason. There was a plan, there was always a plan, and at the moment, John trusted Sherlock a hell of a lot more than he trusted his wife.

He pulled off his coat and dropped it wearily in the kitchen, somehow unsurprised when Mrs Hudson came out of the kitchen as if he had only left her there just minutes before.

'John!' she said, but somehow he could not bring himself to acknowledge her. Then Mary came into the room and lastly Sherlock, obviously struggling even with the effort of the stairs, pulling himself up on the bannister.

'Oh Sherlock! Oh good gracious you look terrible!' she exclaimed as he came in. And so he did, waxy pale, and panting still with the effort of the stairs.

'Get me some morphine from your kitchen, I've run out,' he said and John felt a jolt of pity for him. Sherlock had been on a PCA. The PCA had been disconnected when he'd left the hospital, the one at Leinster Gardens only a dummy. He must be in agony. But why he thought Mrs Hudson would have morphine in her kitchen he had no idea. Some tramadol, some diazepam perhaps, but morphine? He'd heard her complain about her hip pain and her inadequate GP many times and morphine derivatives had never been mentioned.

'I don't have any morphine,' she told Sherlock and John feel a flash of relief, Their Landlady hiding Sherlock's stash for him was something not even Mycroft had ever considered and would have been a step too far, even for John.

'What is going on?' she asked, looking round at them all. Sherlock pale as a ghost, supporting himself against the wall, Mary looking as if - well as if her husband had just found out that every word that she'd said to him about her past was a lie and that her secret identity as a paid killer had just been revealed to him. And John himself? He could only imagine how he must look. Like a man whose world had suddenly imploded. That was how he felt.

'Bloody good question,' he replied, realising he had absolutely no idea why they were there. Sherlock had done the big reveal, he'd proved how clever he was, he'd gained a confession from Mary and also something approximating an explanation for landing Sherlock in hospital but not in Molly's mortuary. He had proved to John that whatever lies Mary had told, that her love for John was not one of them. But then why here? Why now? Why not allow John to take him back to hospital to get the treatment that he needed and more to the point the morphine?

'Trust me,' he had said to John, and John did. He would trust Sherlock with his last breath, and if Sherlock had brought them here then it must be for a reason. But whatever reason he was expecting, it was certainly not the one that came out of Sherlock's mouth next.

'The Watsons are about to have a domestic, and fairly quickly, I hope, because we've got work to do.'

A domestic? What did Sherlock think this was? Some sort of twisted version of Relate? And suddenly John had had enough - enough of this situation, enough of being stuck in a room with his lying wife and enough of Sherlock Holmes trying to run his life for him. If he thought that he was going to just kiss and make up with Mary so that they could get on with the bloody case then he had another thought coming. Did he think that John was just going to forgive her? He was torn for a moment between shouting at Sherlock, and shouting at Mary. But in the end, it was his anger for her that won out. He checked himself for just a second, making sure that he could keep himself under some kind of control before he walked up to her.

'I have a better question,' he said. 'Is everyone I've ever met a psychopath?'

It was Sherlock who replied. 'Yes,' he said quietly and Mary just gave a tiny nod of agreement and they were back to silently staring at each other.

'Good that we've settled that,' Sherlock said hurriedly, yet again breaking the uncomfortable silence. 'Anyway, we...'

And then John finally lost it. 'SHUT UP!' he yelled - at Sherlock, at Mary, at the whole bloody universe. 'And stay shut up, because this is not funny. Not this time.'

Sherlock's quiet reply was lost on him as he turned back to Mary, and suddenly he knew exactly what he needed to say to her. It was a litlle like the cognitive trick that he'd learnt from Ella, really. You just spoke without allowing the words to be filtered. He had no desire to protect her, no desire to protect himself, not anymore. He just wanted to get this over with. And he wanted to let her know, so there could be no possible doubt, exactly what she had done to him. This woman who had come into his life when he had been left broken and empty by Sherlock's presumed death, and had given his future back to him. This woman who had let him believe that he could have a normal life: a home that didn't have a chemistry lab in the kitchen and eyeballs in the fridge; a normal job that okay involved putting your fingers up people's bottoms on a regular basis, but at least didn't involve being shot at or blown up by psychopaths, unless he chose to do that in his spare time; a wife, and soon a child. She had let him glimpse a happy ever after future and then stolen it away from him. And he was absolutely furious about it.

'You,' he said. 'What have I ever done - hmmm? My whole life - to deserve you.'

Mary remained silent, and again it was Sherlock who answered for her. 'Everything,' he said.

'Sherlock, I've told you,' John said in exasperation, 'Shut up.'

But Sherlock obviously wasn't going to shut up, and Mary wasn't going to be the one to interrupt him. 'Oh, I mean it, seriously. Everything – everything you've ever done is what you did.'

John stared at his friend, trying to make sense of his words. So this was all his fault? And then he recognised that look in Sherlock's eyes, He was about to be deduced, and he wasn't in the mood.

'Sherlock, one more word and you will not need morphine,' he told him, struggling to remain in control of his anger once more. Knowing how good it would feel to just give in and lash out at somebody, anybody, anything, but knowing that if he gave in then he wouldn't be able to stop.

'You were a doctor who went to war.' Oh God help him it was too late. And he knew how impossible it was to stop Sherlock mid-deduction. A precisely placed punch might do it, just one punch, he could stop at that surely as long as it was a good enough punch to ensure Sherlock kept his mouth. It would be a damage limitation exercise, he reasoned to himself, and in the end it was only concern for Sherlock's injuries that stopped him.

'You're a man who couldn't stay in the suburbs for more than a month without storming a crack den and beating up a junkie. Your best friend is a sociopath who solves crimes as an alternative to getting high. That's me, by the way,' he gave John an ironic wave. 'Hello.'

'Even the landlady used to run a drug cartel,' he said pointing at Mrs H. Seriously? He'd known that Mrs H's husband had been involved in dodgy dealings, but a drug cartel? Really?

'It was my husband's cartel. I was just typing,' she protested. No wonder Sherlock had thought she might have morphing in her kitchen.

'And exotic dancing,' Sherlock pointed out. Now that brought up images that John didn't want to think about.

'Sherlock Holmes, if you've been YouTube-ing...'

It would have been almost funny if the situation wasn't so serious. The idea of Sherlock looking at - no, that was somewhere he just didn't want his mind to go. He almost looked at Mary, knowing that she would find it as amusing as he did, but stopped himself just in time, remembering why they were there.

'John, you are addicted to a certain lifestyle,' Sherlock was continuing. 'You're abnormally attracted to dangerous situations and people. So is it truly such a surprise that the woman you've fallen in love with conforms to that pattern?'

What was he saying? That he had chosen Mary because he had seen her for what she was? Because he had seen that she was dangerous, that she had secrets, that's she was a woman who could and would do anything, and he had been attracted to that?

No! Not her, not Mary. Everybody else in his life, maybe, but not her. 'But, she wasn't supposed to be like that!' He blurted out, 'Why is she like that?' For the first time, he actually heard something of the distress he was feeling creep into his voice.

Sherlock's face contained a strange mixture of sorrow and compassion and something else, something deeper that John could not begin to identify.

'Because you chose her,' he said finally, and so definitively that John knew that It had to be true, he stood there, staring at his friend, wanting to argue with him, wanting him to say something - anything to absolve John of responsibility for this, but it didn't come.

'Why is everything - always - MY FAULT?' he shouted, furiously kicking out at the table next to Sherlock's chair, so that it flew across the room a short distance.

Mrs Hudson looked shocked, and murmured a warning about the neighbours. Even Sherlock jumped a little, perhaps wondering if he was next for the attack, but Mary, Mary the assassin, didn't even flinch. He turned towards her, watching her calm expression. How had he not realised? How had he not recognised her for what she was? He was a soldier for fuck's sake. He knew the hardness in a man's eyes when they could go out on patrol and shoot other human beings and then come back and laugh with their mates in the mess that evening as if nothing had happened. How could he not have recognised that look in her?

Sherlock's voice broke through the anger that threatened to consume him.

'John, listen. Be calm and answer me. What is she?'

'My lying wife?' John spat out.

'No. What is she?'

'The woman who's carrying my child who has lied to me since the day I met her?'

'No. Not in this flat; not in this room. Right here, right now, what is she?'

Bloody Sherlock. Of course. That what was he had brought her here, to 221B Baker Street. Because he knew that it was the only way that he could enable John to have to hear the facts, clearly and dispassionately, to be forced to look at this objectively. And there had to be a reason. For some reason, Sherlock seemed to think that Mary's story needed hearing. What was it he'd said to John only a few short hours ago, when he had only the tiniest inkling of how his life as going to be turned upside down? 'It's not what you think.'

There was more to it. That was what Sherlock was trying to tell him. 'I'll take the case,' he had said to Mary. And he only took the case when it was interesting, or challenging, or when he liked the individual concerned. Sherlock genuinely liked Mary, John was aware of that. Not just for John's sake but for her own and Sherlock, whatever his flaws, was an excellent judge of character. So if he saw something in his lying, deceitful wife that John did not, then John could only do what he always did. He had to let Sherlock take the lead and follow this wherever it took him as he always did.

'Okay,' he said, turning to Sherlock before turning to contemplate his wife again, wondering how many more revelations this evening would hold. 'Your way. Always your way.'

He pulled out a chair and placed it where they always sat their clients, then sat down in his own chair, opposite Sherlock's.

'Sit,' he said to Mary,

'Why?'

She didn't even look sorry; she just looked - petulant almost, like a stubborn teenager who didn't want to be told what to do. Well not anymore. He was in charge now - him and Sherlock, and there was no way he was going to let Mary get out of this room until he knew exactly what was going on.

'Because that's where they sit,' he said, pointing at the chair while struggling to keep his voice calm. 'The people who come in here with their stories. The clients – that's all you are now, Mary. You're a client. This is where you sit and talk and this is where we sit and listen, then we decide if we want you or not.'

And Sherlock walked across to his chair, slowly, painfully and sat himself down opposite John, and for a moment he thought that Mary might refuse, but a look passed between her and Sherlock. 'She trusts him,' John realised with a start. 'She trusts him to do what is right.'

And Mary did as she was asked and took her seat on the chair before turning to John, for all the world as if she was at a job interview, and waited for him to start talking.