We have done this dance so many times. Centuries have passed where we played this delicate waltz around each other: analyzing the twisted tangles of our intertwined fate, but never tasting the sweet fruit of reward, of being fully together.
I have watched your eyes gain a translucent, otherworldly cast in this lifetime and the next and the next. A pall comes over you as the machinations of that brilliant creature you keep in your head hunt down every last scrap of understanding that you can wrestle from the grimy grip of this hateful world. When the spell breaks and you return to the land of the living, those crystal balls you use to see through me light up with a fire I have searched the world to recreate. The pattern is always the same, no matter if you're my African witchdoctor or my Indian banker or my English consulting detective (the only in the world, you whisper, and it's such a turn on to feel such a rare animal screaming beneath me) and your reasoning is always a tantalizing ghost I can never touch, a specter I wrap my fingers around only to clutch at smoke.
And I have watched you run – incredible thing you are – through the fires of the French Revolution and the screaming horror of the Vietnam War and the awful, hateful rot of the Black Plague to find me. It seems that no matter where I go, death follows close on my heels, and you are clinging to Death's coattails, wresting me from his bony grip with a lion's roar. You run, no matter the body, the same: a concentrated bullet, a straight streaking line through whatever misery I've entrapped myself in, your face immobile with the pure intent of your protectiveness. The strategies of war have changed, the enemies have gained new faces, but the inevitability of my salvation (death by Sherlock, you called it once, in this lifetime, and I smirked and licked the blood from your face) remains the same.
Somehow, along the long string of lives that we've wound around each other, we've come to know each other in a moment. The first hundred lifetimes were long tangos of denying our precious curse, that feeling of understanding another person in totality with only a single glance. Sometimes one of us is slower to remember than the other (and it's often you, you tell me ruefully, stroking at my scars), but now we simply see, like seeking an old love among a crowd: they are different in body, but the personhood – the soul – has remained the same. Perhaps the millennia of exposure to your deduction have sharpened my own dull understanding of the world beyond the flesh.
It is no longer a tragedy, then, when one of us dies: it is only a long and lonely wait, a quiet walk down an empty street to greet a very dear friend. Sometimes in the space between living we try to count the times we've both died alone; it is rare that we are granted the gift of being able to hold each other as we slip off once more. We try to guess when we'll be rewarded for our loyalty next.
I smile a little at the foggy, half-imagined memory of our conversations before we were Sherlock and John, Holmes and Watson, and then I am brought back to reality by the sharp pain of dying. I've been shot in the chest while trying to protect you, but it was too late, and now we lie sprawled together, our blood mixing and melting into the earth, like an offering.
"It's usually the other way around," you wheeze, struggling to speak with your punctured lung, and I shush you with a kiss, pressing my hand to your bubbling wound.
"But I was right this time, about dying together. You owe me," I whisper, stroking back your sticky curls and remembering all of your other faces.
"I'll try to be prettier next time," you gargle, falling silent as the lifeforce drains from your form.
"Impossible," I reply, smiling gently, watching as you struggle to focus on my eyes. "You're always perfect to me."
"And you to me. John-"
"We'll talk about this later," I slur, feeling myself grow limp, the blood loss beyond any salvation. "We always do."