A/N: An 'in-between-quel' that explains why there was so much sexual tension between John and Sherlock in A Game of Shadows. Lots of angst, some smut. Tried to stay true to the characters as much as possible, and also avoid too much in the way of explicit narrative. I worked on the assumption that AGoS took place in February or March, and Watson/Holmes didn't see each other between these events and the movie. Enjoy!

It was Christmas again, the first Christmas I would be spending without my friend Sherlock Holmes at 221B. To be fair, I had reason enough to not spend it with him- I was preparing for my impending nuptials with Mary and had greatly enjoyed spending a quiet Christmas day with her and her family. Still, as the evening approached and Mary and I were sitting and reading in the drawing room of her parent's house opposite Hyde Park, I couldn't help but feel... amiss. I was expected to stay the night there- in the guest bedroom, of course; this was, after all, a proper Victorian household- but as the clock ticked further all I could picture was Sherlock sitting alone in his study, perhaps playing the violin, or- even more concerning- consuming various unhealthy home-made cocktails in an attempt to forget about the holiday all together.

I couldn't stand it anymore. I knew a stuffy Christmas was what was expected of me, but that didn't mean I had to endure it. I stood suddenly and leaned over Mary to kiss her forehead. 'I have to go. Holmes...' I said, hoping she'd understand. She grabbed my hand as I turned away.

'Oh, alright,' she acquiesced, 'give him my best wishes, if you must.'

'I shall, my dear. Please tell your parents thank you for me, if I do not make it back before bedtime.'

She grabbed me by the collar and tugged me into a kiss. All I could think of was my friend alone and when she attempted to deepen the kiss I pulled away from her. We had a lifetime of Christmases ahead of us, whereas I could never be sure of Sherlock. I strode briskly out of the room, through the maze of hallways, grabbed my coat and hat at the door and exited the house into the street, where a few wispy snowflakes danced in the light coming from the door.

Nearly a half-hour later, I had arrived at 221B Baker St. The lights were out inside, but the door, as usual, was unlocked, so I opened it and walked in. 'Hello?' I called into the apparently empty house. There was no return greeting, and all of a sudden my foolishness crashed down around me. I walked up the stairs, cursing Sherlock under my breath for getting under my skin and making me feel the need to check on him, despite the fact that we hadn't spoken in nearly a month. When I arrived at my former study I flipped on the light and sunk into a chair, furious with myself.

Suddenly I heard music coming from the room down the hall. It was a slow waltz, scratchy, as if the record had been left without a cover for some time. I tiptoed down the hall and opened the door to the room the music was coming from- Holmes' room, of course. The door was slightly ajar so I peered in. He was waltzing around the room with an invisible partner. I shook my head, not sure if he was drunk or just being his normal, bizarre self. 'Mind if I cut in?' I asked, and he turned around. He wasn't even startled.

'Watson! I knew you'd be here soon. Please, join me,' he said, holding out his hand. I opened the door completely and took the offered hand. I didn't know how he knew I would come tonight, although I suppose that as a master judge of character he could certainly deduce that my feelings for him were far stronger than casual acquaintance and I couldn't actually have a Christmas without him.

'I can't actually dance, Sherlock,' I said. This was embarrassing, especially considering my upcoming wedding, but between medical school, my time in the army, and my adventures with Sherlock I had never had the time to attend balls or even get Mary to teach me.

'Not a problem, because I can, and I am nothing if not an excellent teacher. Here- first, I shall lead, and you can take the role of the blushing bride. Don't look at me like that,' he said, noticing the shocked expression on my face at the implication that I was the woman in this relationship, 'it's better if you learn the more difficult role first, it will make you a more... empathetic leader.'

'Fine,' I said, covering his left hand with my right and putting my left on his shoulder, while he put his right at the small of my back. It was strange, being this physically close to him, or it would be for any other pair of men, but he and I had transcended mere friendship through our work together. Suddenly it occurred to me what I would be missing when I ended our partnership to marry Mary. I looked him in the eyes and saw in his the reflection of the same thoughts I was having. But the moment passed, and I returned my gaze to the floor where I knew I could keep track of my feet.

'I am going to teach you the basic box step, the foundation for every waltz. When I put my left foot forward, you in turn move your right back. Then, simultaneously, I move my right to the side while your left mirrors mine. Good- now, bring your feet together again at your left foot's new position. That's one measure. The next begins in reverse- you put your left foot forward while I move my right back, then your right to the side, followed by your left meeting your right. That's the next measure. Backward - to the side - together; forward - to the side - together. One – two – three; one – two – three...' We continued in this manner until I got the hang of it, and were eventually able to keep in time to the last few bars of music. The recording ended with a scratch and Sherlock and I were left with a silence hanging between us as we were still holding each other quite close. 'I'll... put another on,' he said, dropping my hand and removing his from my back.

Another scratch of vinyl and a new, slightly quicker waltz began. 'Now that you understand the steps, I must teach you the more advanced art of spinning,' said Sherlock. We resumed our positions from moments ago and he began counting the beat under his breath. With a nod, he began the box step again with me following. 'In a few measures, I am going to spin you out for a count of three, and then back in for the next count. Do you think you can manage it?'

'I'll do my best,' I replied, although to be perfectly honest I was finding it harder and harder to concentrate with the thoughts of my impending separation from him dancing around my head as we were. I had already moved most of my possessions out of 221B and into my flat, and only needed one more trip to be complete. I had been planning to come back the day before my wedding in a few weeks, incidentally the day of my stag party, which Sherlock was supposed to organise.

'Watson!' said Sherlock, and I snapped out of my reverie to feel the pressure on my right hand indicating he was about to lead me into the spin. 'One – two – three,' he counted, as I let go of his shoulder and very un-gracefully spun beneath his outstretched left arm. On his next count of 'one', I crossed my left arm across my chest and wound myself back into him. But I misjudged where he was and instead of a graceful return to position, I shoulder-checked his chest and we fell together onto the floor with me on top. I was scrambling to push myself off him when I noticed the look in his eyes had returned- the one that spoke volumes, the one that sent a shiver down my spine and made my heart flurry. I sat back on my heels while he righted himself into a seated position, his legs stretched to either side of me.

'John-' he said, but I'm not sure what was going to follow because I leaned forward, balanced on my hands, and kissed him, lightly, on the lips.

Even I was shocked. I had never had feelings for a man before, not in the same way I felt attracted to women. But Sherlock was different; he always had been. Our relationship had grown from an initial working partnership and sharing of resources and living space to one where I truly felt amiss when he wasn't there to bounce ideas off of. This past month of living away from him to prepare my new home had been hell in every sense of the word.

With my mind racing, full of these realisations, I barely could register the expression on Sherlock's face. As it turned out, though, I didn't need to think through his response at all. He took my head in one of his hands and pulled me forward again so he could kiss me, properly, and before I knew it, I was kissing him back.

After that point, my overly-analytical thoughts froze and I acted on simple instinct. Fumbling with tongues and mouths turned soon to a trail of kisses along my jaw line and discarded neckties. Soon we were standing again, mouths locked, with him pushing me aggressively back against the wall and me pulling at the buttons on his shirt. I still wasn't entirely sure where this was going but I was in no mind to stop it, either. When I finally got his shirt open, I ran my hands over the lightly haired planes of his chest. I had done this with Mary before, but just once, during an extremely passionate reunion with her following the Blackwood incident. Nothing with her could compare to this, though. As Sherlock forcibly pulled apart my own shirt, I felt as if we were sharing thoughts; one soul in two bodies, desperately trying to be reunited. Once both our chests were bare I pressed myself to him tightly, craving the warmth of his skin against mine. It wasn't until his hands were pulling apart the buttons of my trousers that my mind finally kicked back into gear. I pulled back from him to catch my breath.

'Sherlock, I am getting married,' I hissed, though it honestly pained be to feel the rush of cool air between our torsos.

He shook his head, and leaned his forehead in to connect with mine. 'John, I know. I know. The knowledge has plagued me, burned through my being for an age now.'

'Why haven't you told me this before? You know I've never wanted to hurt you. You're more than my friend- you're my partner; you're one of the only men I trust completely.'

'For those very reasons, John. I know that Mary makes you happy and it is not my place to take away the happiness of the only person I've ever...' he paused, 'needed, as much as I need to breathe oxygen.'

I wanted to slap him. He could say all he wanted about not wishing to drive a wedge between Mary and I, but confessing his feelings in the same breath completely negated his previous pronouncement. The choice was before me: I could give in to my desires for Sherlock, could show the man the true amount of my love for him. Or, I could leave right now, walk out of his life, return to Mary and spend the rest of my days wondering 'what if?'. It wasn't even a choice, really.

'You bastard,' I said, and locked my mouth to his.

Clothes were torn with ferocity. Buttons popped, suspenders snapped. I pushed Sherlock onto his bed and climbed on top of him. His hands were at my waist again, eagerly pulling apart my trousers. I gasped when his hand brushed across my cock; I had finally divested him of his own pants, and my hands were on him, everywhere, exploring his skin, the jut of his hip bones, the trail of fine hairs on his stomach. I drew my mouth slowly, torturously down his body, pausing now and then to look up and see his face- his eyes half-lidded, his mouth slack, his breathing hitching whenever my tongue brushed a particularly sensitive spot. I didn't hesitate to take his length into my mouth, and the noise he made when I did so will forever be burned into my cranium. I worked at him with tongue and fingers, feeling his body tighten as I administered myself to him. The things I was doing to his body were guided by instinct, based on what felt good on myself and the wordless messages he was sending me.

'John,' he gasped, and I felt his powerful arms pulling me away, releasing his cock from my mouth, drawing me up so we were face-to-face again. In one swift motion he flipped us over and pinned me to the bed beneath him. His calloused, rough hands were doing indescribable things to me. I felt a finger probing, asking permission, and I nodded, breathless.

Our lovemaking was not a thing of beauty. It was rough and somewhat painful as he buried himself within me after working me open with his fingers, but the fullness he gave me took my breath- and all coherent thought with it- away. I licked at the salt on his collarbone and pulled on the pulse point at his neck with my lips. His fingers dug into my ribs and his teeth were nipping at the curve between my neck and shoulders, leaving behind imprints that I was sure would bruise purple and black in the morning. The friction of my cock against his taut stomach made me ache, it felt so good. I could feel an edge approaching and by the raggedness of his breathing and the way his thrusts were growing more erratic, I knew he was nearing that same point. We fell within seconds of each other, my nails digging into his angel bones and my name on his lips as we clung desperately to each other, each an anchor within the other's storm of passion.

I felt the loss acutely as we separated. My eyes were squeezed shut because I couldn't bear to look at him, to see the look in his eyes and the evidence of our sin painted on the bed sheets. We were spent, exhausted, laying side-by-side with him on his stomach and I on my back, his arm draped over my chest, rising and falling with each breath I forced into my lungs. Gradually our breathing evened out and I could feel unconsciousness tugging at my mind. 'I should say something,' I thought, but we were both too far gone to dissect this event. He pulled me so I was on my side and my back was against his chest, our legs entangled below us. In that manner, we drifted off to sleep.

I awoke as dawn's sunlight brushed gently across my face. I wasn't cold- Sherlock must have gotten up some time before me and considerately covered me with his quilt. It begged the question, though- where had he gone? I pushed myself up in bed and stretched my sore muscles. I could feel the predicted bruises that had bloomed on my shoulders, and winced as the memories of the night before flooded back. Sherlock was sitting at the edge of the bed, fully clothed, his left ankle resting on his right thigh and his fingers steepled beneath his chin as he appeared to survey the window. I rolled off the opposite side of the bed and hastily gathered what I could find of my clothes, scattered as they were on the hardwood floor.

'Sherlock,' I said, once I was sufficiently robed to face him. He turned his gaze away from the window and met mine, and on his face I could see both the concern in the crease of his brow and the understanding in his eyes. I leaned against the desk.

'John, my dear friend. I know what you will say, so you don't need to bother with the unnecessary apologies. It was a mistake, a moment of passion buried beneath regret. I can see that you intend to leave me here and nothing I say will convince you otherwise.'

I shook my head. 'You are correct in some respects, but you may be astonished to learn that I don't feel regret for what transpired last night. No-' he opened his mouth to interrupt but I cut him off, 'I do need to leave. I am engaged to be married, and I intend to carry through with my promises. I love Mary,' and here I choked on my words, for who could claim to truly love one when looking into the eyes of another and feeling the same for them?

'But...' Sherlock continued for me, his gaze piercing me.

'But,' I offered, and steeled myself for what was to come next. 'I love you, as well. I wish I could leave, untie myself from my commitments, and build a life with you filled with adventure. You mean more to me than any human being has before.'

The shock in his expression gave way to compassionate sadness. He knew, as did I, that the picture I had just painted of a life together could never be more than a dream. 'So, you will leave, then. To live a sinless life in holy matrimony,' he said.

'Yes, Sherlock. I'll return the day before my wedding to collect the rest of my belongings.' I bent to retrieve my coat from the floor, and turned to leave.

As I paused in the doorway, he stood, took the three steps to cross the distance between us and wordlessly wrapped his arms around me. Our mouths came together once more, for what we both knew had to be the last time. The kiss was slower and gentler than any from the night before- less of a furious passion and more of a slow smolder. In it we placed all the desire, all the feelings of comfort and friendship we had ever given each other.

'The only regret I have,' I whispered, 'is leaving today to fulfil my duties.'

'I know,' he replied, uncharacteristically without sarcasm or sass- just honesty. 'I know.'