Lost Between Worlds

Who am I?

I'm being rocked back and forth on a soft surface. By who? I don't know. I can hear them saying something... But they're so far away...

And everything goes black.

In an amount of time that simultaneously feels like forever and not at all, I can feel again. My head's pounding. I'm still being rocked, although it's more violent now. The person is still talking. Now it's audible, but barely above a whisper. It's just loud enough to make out...

"John. John. John."

Just that one word, spoken over, and over, and over... Then it stops. I feel small slaps on my cheeks.

"John? John, can you hear me?"

I groggily open my eyes. It's a man, looming over me. It takes a minute, but my eyes focus. My breath catches.

"Sh- Sher-" I say, shaking now.

"Don't speak. I'll get Mrs. Hudson." The man turns, about to walk away.

"No," I manage to say. Wait. Was that me? It didn't sound like me...

"What did you say?" I try sitting up. The room spins around me, and I fall back again. "John, you aren't feeling well."

"This can't be..." My breathing becomes irregular and my pulse quickens. "This isn't my voice... You can't be Sherlock... You don't exist..."

"John, you're scaring me. You need a doctor."

"Little vain, aren't you?" I say, slipping into the darkness for a minute. Why did I say that? When my vision returns, the man looks taken aback. "Please, whoever you are, I'm trusting you to trust me. Don't call a doctor, and don't tell anyone about this... Promise me..." I'm growing faint again.

"I... I promise." And I go under once more.