It was a cold late afternoon in London. Clouds had cuddled over the city, pouring down rain hard upon the rushing tourists. The streets had not been as busy that day, and especially on Baker Street, where things were calm for a change.
John Watson had left with his girlfriend just a few minutes ago, taking her on some fancy dinner that Sherlock couldn't understand the meaning of. But it didn't matter, for he was finally alone, the flat free from John's complaints and utterly ordinary presence, and Sherlock was at last only by himself and his violin.
He was composing tonight. And his melody had became one with the sound of the raindrops hitting the window, and it was beautiful. Holmes had written three pages of notes already, a varying tune with a soft rhythm that grew into a tension, a tension so intense that it even bothered him. What was the plot to this tune? He would never know. Music was the mystery he could never solve.
"Music is like math, you know." said Moriarty, stepping inside the apartment with slow, long strides and a bright smile.
Sherlock froze in place, right in front of the window, his back turned to the criminal.
"So precise" the madman spoke softly. "So beautiful, correct, logical. Like you."
"You said beautiful" Sherlock spoke in a slow, gentle manner, his voice low and pure.
"I did."
A silence followed. And then Jim's footsteps. One, two. Stop. Three, four, five.
He was inches behind the detective; close enough so that his warm breath would brush up Sherlock's neck ever so slightly. Moriarty took one of his dark curls in between his fingers and played with it. Then he let it go, fingers trailing a path down the neck and behind the ear with a light, soft touch.
The sensation was an overwhelming tease for both of them.
Jim leaned in quickly and his tongue gently darted out to touch Sherlock's ear, and the detective drew a fast sharp breath in surprise.
"Don't panic." Moriarty accused him mockingly and let his tongue slide up and down the warm skin. "I won't hurt you." he claimed with a whisper and placed soft kisses on his neck, smiling at the goosebumps, at the excited skin.
The criminal slowly took off Sherlock's robe, letting it fall down to the floor with grace. Sherlock put the violin aside, next to the note sheets, and closed his eyes, letting himself go.
From behind the taller man's back, Moriarty unbuttoned the purple shirt, and slid it off of Holmes, leaving him bare-chested.
Even though the room swam in the warmth coming from the fireplace, Sherlock got goosebumps all over, his skin exposed and ashamed and excited.
Moriarty kept kissing his neck and his shoulder, the detective feeling the grins of the criminal upon his own bare skin. It felt warmer, more comfortable now, under Jim's touch; under his thin fingers which ran gently and lovingly over his own hand.
Sherlock turned around, Moriarty's eyes seeing his. Two equal minds racing with sharpness and clarity and passion and lust, two minds collaborating, their thoughts turning into one, two minds connecting wordlessly. And then their lips crashed together, but gently, they did it gently and slowly, with passion and meaning.
As they were kissing, Moriarty, with his ghostly touch, took Sherlock's hand in his, and intertwined their fingers. Warm skin on warm skin, soft lips on soft lips. Equality.
Love is like math, you see, Sherlock, Moriarty thought, not wanting to speak, because he would have to break the kiss. It's an equation. Composed by logic and rules and beauty. But it all dissolves in my mind when you touch me. I forget the definition of love. I don't know it anymore. I only feel. And feeling feels so good. Nothing can replace that, Sherlock. Nothing can replace you.