Author's note: I've been on a seminar the past two days, and on each day I came home and had close to twenty messages waiting for me about people favouriting my stories or commenting on my stories or even me – I am so honoured, and it always brought a smile to my face, no matter that I'd just spent nine hours at university. Thank you all so much.

This wouldn't leave me alone.

I don't own anything, please review.

For once I am the one pacing up and down. I am pacing up my room, however, not running around the whole flat with my arms flying around. I know Sherlock can hear me; I know he is worried – a word most people wouldn't associate with him, but I've seen a different side to Sherlock Holmes.

I've always been able to see it, to be honest. You don't pay homeless people for (sometimes useless) information or cure your flatmate of his psychosomatic limp if you're a sociopath.

Most people would probably think I'd hate him for leaving me for three years, three years I spent grieving, three years of leading a totally unremarkable life. But he's explained everything to me – as soon as he recovered from the blow (I made his nose bleed and still feel bad about it – naturally, I simply can't take any satisfaction out of having made him suffer). And I understand. I do. Even if I'm still a little angry, and will probably remain so for some time.

But the important – the most important – thing is that he's back, here, at 221B, with me.

I'd left it after he had, but I came back after a year. I couldn't bear to live anywhere else. Here it was that so many of our adventures had begun, here it was where I chose to stay, no matter how much Mary pressed me to move in with her. Maybe my refusal to let go of the past was what made her leave in the end. It was better this way; I'd take Sherlock being alive over a life with her any day, and therefore I clearly don't deserve her. Maybe I'm crazy, maybe I've been crazy ever since I moved in with the consulting detective, but I couldn't care less. My place is here.

But I saw the worried look in Sherlock's eyes when I simply said "I'm going to bed" right after we'd caught Moran and went upstairs. He's worried I might leave. I don't know how I know, I just do.

I won't leave. I'll never leave, not unless he decides he's better off on his own, and, judging by the fact that he spent the last three years making sure we – me, Mrs. Hudson, Greg – were safe, I highly doubt he'll ever think that way. So this is not the reason I am pacing.

Him coming back from the dead after three years and my anger about having been left in the dark isn't the reason either.

Nor is the fact that he has already filled the fridge with body parts. I don't mind. To be honest, I missed his experiments just as much as I missed him.

The reason is surprisingly simple.

Colonel Sebastian Moran.

Not because capturing him was dangerous; we have been through a lot together and, quite frankly, I had no doubt we'd win. He's fit and strong alright, but it was two against one.

Yet – and I know it's probably silly –

Moriarty. I'll remember him for as long as I live. He was cruel, he was heartless, he was –

He was brilliant, he could deceive other people, he could get anything he wanted –

He was Sherlock, if my best friend had ever decided to become a villain instead of a hero (though I'll never tell him I see him as one). He was Sherlock who'd chosen the wrong path. He was Sherlock lost in the darkness.

He was Sherlock's mirror image. Somehow the same, but somehow completely different. The polar opposite of Sherlock Holmes.

And Sebastian Moran –

He's mine.

I know Sherlock doesn't see it that way. He'd probably laugh in that deep voice of his and say, "Be serious, John. You are a normal, completely ordinary human being" and leave it at that. But I know better.

Of course I could have gone wrong. My father was an alcoholic who occasionally hit our mother, though he never touched us, and Harry soon followed him on the path of no return. And the army isn't really known for creating well-balanced personalities. That isn't to say that the army creates psychopaths. I know many good soldiers who are also good men.

But shooting and killing and healing and all together leave their traces.

And, from what Sherlock told me, Colonel Moran's career was that of a remarkable, good soldier up to a point where suddenly, everything went wrong. If I remember correctly, he compared it to a tree who grows straight in his youth and then suddenly develops a deformity in its growth.

What if I had gone the same way? Slowly losing myself in a world of crime until a criminal mastermind came along and took me under his wing? Until I became his sniper, his – his pet, always there when he needed me?

Maybe I wouldn't even have needed to be a criminal first.

If I hadn't met Sherlock, but Moriarty all those years ago, what would I have done? Would I have run? Would I have laughed into his face, because I could never become a monster like him?

Or would I have – would I have joined him, because there was nothing else I could do? Nothing else that would make me feel alive?

The thought that I could have been one of the snipers who were ready to shoot Sherlock at the pool sends a cold shiver down my spine.

Perhaps I was just lucky that I met Sherlock, and not Moriarty, like Moran did. He didn't really commit a capital crime until Moriarty came along, that's what Sherlock tells me. Maybe I could have gone the same way. Maybe it's all about being at the right place at the right time, and I was, and Moran wasn't.

Maybe, according to him, he was. He cared enough for Moriarty to want to avenge his death – his suicide – over three years after he'd lost his friend, after all.

And it scares me that, should something similar ever happen to Sherlock, I wouldn't rest until I'd taken my revenge either.

Me and Sherlock. Moran and Moriarty.

Two teams.

They were inseparable, just like we are. The only difference is that we are on different sides, really.

What did Moriarty say again, according to Sherlock? Oh, right –

We are on the side of the angel. They were on the side of the devil.

And how easily we could have gone down the same road.

Because I wouldn't have left Sherlock alone, no matter which side he was on. I would probably have run if Moriarty had come (though I can't be sure about that), but I'd never have left Sherlock's side. I need him. He needs me. It's as simple as that.

How well I can understand Moran.

Apparently he met Moriarty after having left the army; after having left his purpose in life. I don't think he was irredeemable at this point. True, he had committed a few crimes, but nothing too serious; he hadn't hurt or killed anyone (except when he was a sniper in the army, but who am I to judge that?) and then Moriarty came along.

The consulting criminal gave him a new purpose.

He was broken, and lost, and didn't know what to do, and had no idea why he'd survived if he was simply destined to lead an utterly unremarkable life. And then –

Someone offered him a new chance, a new beginning, and he knew it was dangerous and illegal, but he took it all the same. He couldn't predict where this road would lead, but he chose it. Just like I did when I limped in the lab. Just like I did when I shot Jeff Hope. Just like I did only a few days ago, when Sherlock returned.

I'm convinced that, if alternate universes exist, somewhere Sherlock and I are the criminals, and Moriarty and Moran fight on the side of the angels.

Sherlock would laugh if I told him everything that's going through my head.

But the thing is –

I'd grown accustomed to Moriarty being the polar opposite of Sherlock Holmes. It was the way things were. I'd never have imagined recognizing myself in a cold-blooded killer.

And one who wouldn't think twice about killing Sherlock at that.

It's unsettling, that's what it is.

Sherlock probably doesn't think much about Moriarty being his mirror image. Sherlock doesn't think like that, or, if he does, it doesn't scare him like Moran scares me.

Because Moran represents everything that might have gone wrong in my life. Everything I could have become. Everything I'm thankfully not.

I'm not him, I was lucky and I made the right choice all those years ago.

But I can't keep pacing up and down my room, Sherlock is probably wondering if I'm packing.

So I return to the living room, where Sherlock is holding his violin on the sofa and staring at me as I walk towards him.

"John" he asks slowly, "is everything alright?"

There are many things I could say. I could say "I'm glad we're not Moriarty or Moran" or "I just had an existential crisis" or even "You are aware that I'd never leave you, right?", but instead, I simply answer, because I know he'll understand, "It's all fine" and he smiles.

It's true. It's all fine. Because we are together, and we are on the side of the angels.

And, suddenly, thinking about Moriarty and Moran, as scary as it is –

I begin to suspect that it all would still be fine, even if we weren't.

Author's note: Just something short to thank you for all the great responses. And I wanted to upload something before I finish "May Each Be Happier Than The Last" on Monday.

This has probably been done before – but I find the parallels between the two teams just fascinating.

I hope you liked it, please review.