Trigger Warning: Major character death.
1
House of Ash
The fire starts as a spark. Small, cautious, contained - a barely flickering glow. The oxygen feeds it, making it grow, until it engulfs anything and everything in its path.
Sherlock barely wakes up in time. He hears the roar of the fire, and the sound of wood collapsing, and thinks it's all a nightmare. Wearily, he opens his eyes and finds the air has been replaced with noxious, thick black smoke. He gasps, inhaling a mouthful of the toxic smoke. Coughing, he nudges John to wake up.
"John, John," he shakes his partner. John doesn't wake up. "John, you've got to wake up."
The smoke is nearly too thick to see now. Sherlock picks John up by the waist, heaving the smaller man over his shoulder. He steps out of the bedroom door to find the hallway engulfed in flames.
He runs - just runs; not thinking of the memories he's leaving behind. Not thinking of their signature chairs by the fireplace, or the skull on the mantle, or the violin by the window, or the yellow smiley on wall littered with bullet holes. He forgets about the milk and the thumbs in the fridge, the Cluedo board stabbed to the wall, and his precious petri-dish experiment next to the biscuits in the cupboard. He runs, because that's the only thing he can do.
Sherlock hears the ceiling crack above them and knows what's about to come. His first instinct is to get John out of the way, and Sherlock moves just in time to dodge the cascade of fiery drywall that comes falling down on top of them. His second instinct is to make sure John's alright, and he makes sure his partner doesn't have any injuries before attending to himself. John is fine. Sherlock, however, is not. No matter; he can attend to that later.
Downstairs, Sherlock calls for Mrs. Hudson. There's no answer. The smoke is thicker downstairs – Point of origin: Likely Mrs. Hudson's faulty iron. If only she'd –
Bits of ceiling fall down again, interrupting Sherlock's thoughts. The ceiling is about to collapse completely. They probably don't have more than a few minutes left. Sherlock runs towards the door. He can (he will; even if the house is reduced to ash) come back for Mrs. Hudson after he gets John to safety.
Sherlock bursts through the front door of 221B and coughs, gasping. He moves forward into the street anyway. An unfamiliar set of hands reaches out to help him, and helps him set John down on the ground.
Safe, Sherlock sighs.John is safe. John is unconscious, but John is safe. He collapses down onto the ground next to John. His throats burns. He's covered in ash and his eyes are spotting, blurred and altered from the smoke. He heaves, gasping.
Sherlock looks towards 221B, and sees that the whole street is on fire. Fire trucks surround them, attempting to put out the blaze. A group of useless civilians stand useless in the street, huddled together and looking frightened.
Mrs. Hudson. Mrs. Hudson is still inside. Sherlock tries to pick himself up off the ground, but he can't. His legs feel like bricks, and his the rest of his body refuses to do what his brain commands. He starts to crawl towards 221B, but the same set of hands that helped him before now pulls him back, keeping him from saving his landlady – his friend.
"Mrs. Hudson!" He screams, pointing at 221B.
Suddenly, Sherlock is hit with an overwhelming sense of dread. The feeling pools into his stomach until it spills out his mouth, and he collapses face-first onto the pavement, exhausted. "Please," he mumbles. Face still on the pavement, he looks up towards 221B. The fire roars and pours out the windows, the crackling sounds like gunshots.
Sherlock closes his eyes, unable to look at the horror any longer. "Oh, god, please…" he whispers. "Please."
...
Note:
Will be six chapters total. Establish Johnlock, Mystrade (both are married). I'm so sorry, Mrs. Hudson.