A/N: Anonymous asked, "I would love you forever if you'd write me some super depressing and yet awesome Sheriarty?" And so I delivered. I think.
"You're obsessed," Sherlock states rather coldly, his voice like venom and his words like blades, the mixture like a slice of poison entering directly into Moriarty's veins.
"And you're not?" he counters fluidly to mask his hurt at the remark. "Yes, all right, I'll admit I'm a bit fascinated with you —"
"You wrote my name repeatedly over the inside of my brother's interrogation chamber like a deranged teenager with a crush, doodling in their notebook. You put little Xs as kisses when you sign your texts to me. You're obsessed" he repeats, "And I am not. You are a challenge, a rather clever and interesting one, yes, but I clearly do not return your feelings, Jim."
"That hurts, Sherlock, it really does," he says with a false pout, but in reality, it does sting quite a bit. He shrugs off Sherlock's death grip on his jacket's lapels and sighs as he steps aside, out of Sherlock's personal space but still under his glare. "Can't you accept my backwards love? We could be perfect together, you and I. The criminal and his detective. We could rule nations, evade and control the law, and all before breakfast after a romping night of hate-sex. Sounds glorious, don't you think~?" and he raises a brow and his voice simultaneously.
Sherlock snorts a bitter laugh. "You must know how ridiculously insane and impossible that sounds."
"Oh, let a man dream, Sherlock," Moriarty pouts again, but his heart clenches in his chest and he adverts his gaze. "So, this then. This little dilemma of ours. We keep 'dying' on each other and springing back up again like zombies, don't we? It's quite bothersome. Maybe we should end it, once and for all."
"…Are you saying… we die for real?" Sherlock remarks cautiously, his eyes narrowed and his guard up, and he raises John Watson's gun, the doctor nowhere to be found.
"Well, yes, of course. Duh," he adds for emphasis. He rolls his eyes. "I'm tired of this game, Sherlock, I really am. It's not fun anymore. You hate me, you killed my best snipers and henchmen, you've taken away my favorite toy, Sebastian, and all for the sake of John and justice and blah blah blah," Moriarty relays with a groan. "Jesus, can't we just end it this time? For real? I just want to die in your arms and be happy on my highway to Hell~." and he sings it and mimics the song with some air guitar and looks like he's on the brink of tears, but it could all be an act. Sherlock has learned not to trust a single thing Moriarty says, even the truths behind the lies, because those could be bluffs for further deceit buried in backward honesty.
"You… want me to kill you?" Sherlock restates bluntly, "So I know it's real and so you can, what, die in peace, ended by your greatest foe to feel accomplished in your life?" and he frowns.
Moriarty rolls his eyes, but in doing so, he lets slip a tear. "Yes. God, are you really so plainfully ordinary after all that you have to state the obvious? I'm tired, Sherlock, and I'm forfeiting." He sighs and takes Sherlock's hand in both of his, the one holding the gun, and presses it tenderly to his chest. "Please. Consider it my dying wish. I'd rather die by your hand than a lethal injection or electric chair or whatever they fancy using for executions these days. There's more justice in it if you do it. And that suits you, doesn't it? —No, don't answer that; rhetorical. Of course it does. You love that you're the only person who can bring me to my knees, who can kill me." And he smirks.
"…No. No. This is a trick, it has to be, just like atop St. Bart's. You don't— you wouldn't—" Sherlock babbles, tripping over his own thoughts with the rate they're whizzing by in his brain. He can almost smell the electricity, can almost feel the oncoming short-circuiting that will make him pass out like an epileptic.
"Goodbye, Sherlock Holmes," James Moriarty whispers, and he kisses Sherlock's white, tendon-taunt knuckles before forcing him to pull the trigger.
He falls into a heap of blood and tears, eyes closed and restful onto the ground.
Sherlock stumbles backward, stunned, and closes his own eyes as he slides down the nearest wall behind him. He presses the heels of his palms to his eyes and wonders what the fuck just happened, and if this is all a nightmare or not.
It must be, he thinks, because he can swear he hears Jim crawling up between his legs and pressing a bloody kiss to his knee before collapsing again, truly dead this time.