A/N: An ideal portrayal of Moran and Moriarty's relationship, in which they are everything to each other, as I like to think they are. I'm not totally happy with how this came out, but pleased enough to post. Enjoy.

Moran was Moriarty's one weakness. It was as simple as that, one of the few things black and white in their complicated... relationship. A relationship in every sense of the word.

After a few months in each other's company, it became clear to the both that there was something off about the other. A thing not discussed in polite society, a thing not even condoned by the law. A thing buried so deep inside each of them it would take another year of suspicion to bring it to the surface. One night's indiscretion on Moran's part had seen to it, however.

It was a cold, wet, dark and moonless night. Perfectly miserable and perfectly London. Moran had left the safe house where he was staying and one of Moriarty's lesser lackeys had been ordered to follow him.

His destination was an unsavory hole where comforts of the most carnal source could be found, and he left it in the arms of another man. From that night on, the suspicions of Moriarty that had been clouded by his own emotions were confirmed, with as much optimism and surprise as the stoic man would allow himself.

And from that night on, their relationship changed. Far be it from Moriarty's prerogative to take what he wanted, as he normally did. The bearded, simply-spoken army man deserved better in his eyes for his unwavering service. It was with great pleasure that Moriarty began to seduce his quarry, an act he was long out of practice with but which came back to him more quickly than he'd anticipated.

Moran proved a bit more simple than Moriarty had hoped, but three months in he finally caught on. Everything culminated in a stolen kiss in the most vile of alleyways, Moran shoved up against a grime-covered brick wall and Moriarty lost in wild abandonment brought on by the most passionate kiss he'd ever given. Is it possible to give everything to another person? All your plans and needs, your insecurities and pride, wrapped up into the feel of flesh against flesh, lips against lips? That's how that night felt for Moriarty.

One could say that that was the night they became more than just master and servant, but it wasn't, not really. Their long, searching glances had always been present. The way they felt had always been there, gently simmering, suppressed by the fear of not being reciprocated. Their mutual devotion had been born the first time they laid eyes on one another, even before their business agreement was formalized.

Suddenly they had new reasons to seek out solitude with each other. Whatever Moriarty asked, Moran would give. And whatever Moriarty gave, Moran would take. The good and the bad. Because Moran was Moriarty's one weakness: and Moran loved him enough to never even contemplate take advantage of it.