Sherlock wakes up because of the light. There's grit in his mouth and in his eyes and down his neck into his clothes, making him itch all over. He opens his eyes and immediately shuts them because the light is so bright it sears. Even minutes later there is a green dot floating in front of his closed eyelids. It's a regular bulb because the filament is a squiggly line of black in the middle of the dot. The back illumination makes the capillaries in his lids visible around the edges.
He tries to raise his arms to wipe some of the dirt away but his arms crash into a solid surface.
He stills himself to take stock. It's a box of some sort. A coffin perhaps, but no padding, no silk lining. The bottom, or rather the end away from his head because he's definitely horizontal, is right up against the soles of his feet, and the top is only an inch or so above his body so that he can't get any kind of leverage to kick out or push up. The sides too are too close for him to do much beyond turn his hands palm down.
By wiggling his hips he's able to move slightly in the direction his head is pointing, but bumps against that side too.
He's not claustrophobic. He used to climb the drawers in his wardrobe to get into the shelf at the top and hide, but he knows that there is a big difference between enjoying wedging yourself into a tight space because you want to, and being trapped in a tight space where you can't get free.
He can hear nothing but his own breathing and the blood throbbing through his body. He could be buried under ground (likely because of the grit, but not certain) or he could be in a sarcophagus in the middle of the British Museum (unlikely because of the silence—sarcophagus are hardly likely to be soundproof—but it could be the middle of the night). Whatever it is, it's made to measure.
What does he remember? There was a case of course. A case…a case involving what appeared to be a couple of random deaths, but he could see that the injuries weren't consistent with where they were found. Was going…going south of the river to investigate. John wouldn't come. Said he thought that Sherlock was wrong and just trying to drum something up.
Why is his mind so fuzzy? Was he drugged? Clunked on the head? No, no bruise he can feel.
Although, now that he examines it, his head does ache and he feels nauseous.
It comes to him far too slowly. He's in a box. The air is stale. His oxygen is running out. He's already suffering from carbon monoxide poisoning. If he's going to be found, it needs to be soon.
There is a moment of lurching panic as his animal reflexes kick in—I'm trapped, I'm trapped, I'm trapped. He manages to talk himself back from that, but getting his breath under control is difficult, more air gone.
Then there's a moment of intellectual distress. Who's going to find him if he's not out there to solve the crime? Scotland Yard? He snorts in disgust. John? Well, John will certainly give it his all.
Of course, do they even know he's disappeared yet? He's disappeared for days before. The first time he returned to find John in a lather and half of Scotland Yard poking through his things looking for 'clues.' Now John's used to it, so he won't know to start searching yet. He has no idea how long he's been here. How long between when he left 221b and woke up here.
Panic and worst case scenarios are counter-productive. He needs to think of a way to get out of this. Surely he can do that. His ears prick up. No, that's ludicrous. Human ears don't move up and down unless you control the muscles carefully and not everyone can do that.
Rambling a bit. But he's sure he heard something. They're going to find him.
"You are an idiot," John says.
"You didn't want to come."
"Don't make this my fault!"
"I'm not. It's good that you didn't want to come. We'd have both ended up buried alive with no one to come looking."
"It wouldn't have come to that. Because I'd have saved you. I always save you."
"Yes, you do." He's reaching towards John to try and show him what he feels, but John just keeps getting further and further away…
He snaps his eyes open, is blinded again and shuts them in pain. He tries to tell himself that the tears running out of the corners of his eyes are from the light and the grit, but he knows better.
He's becoming delirious, he realizes. He feels lightheaded and vertiginous, even though he's lying down and the flush he feels through his chest isn't from the lamp, it's from the buildup of carbon monoxide in his system. His extremities are painfully cold. The headache and nausea are excruciating and he hopes that he won't throw-up and choke, although he's really only got a short time to live. He'll fall asleep soon from the gas his heart will stop in his sleep. Choking, on the other hand, is a horrible way to die. Actually, is there any good way to die? It's just that some ways are more painful than others.
John was right, he thinks. I want to pray, to pray to God that I live, but I can't, because he's not there. I want to pray to John to come find me.
They were right. The woman in pink wasn't writing her password, she was thinking of her daughter; it was just a lucky coincidence that it was also her password, or that was a tribute too. He can't think of anything to scratch into the wood that would help because he has no idea who has killed him. He wants to write I love you, John. You were the best thing that ever happened to me and I didn't know it. Well, maybe not the whole sentence, but if he could move his hands enough, he would write 'John' with the last of his strength and never mind the pain.
It's stupid because there isn't any reason to think that the words would ever be seen. If they haven't found him by now, then it's unlikely that they ever will.
It's impossible not to slip into sleep. He feels like his mind is unraveling thread by thread, thought by thought. His last thought is of John.
The sounds come up like voices on an old radio warming-up.
"I'm going with him in the ambulance."
"What relation are you to him?"
"I'm his doctor; I'm his lover. I'm anything that will let me come with him."
His lungs feel half frozen with the cold air, but he's giddy with the joy of it. Or maybe that's just the gas. His body has already been taking great lung-fulls of air while he was unconscious, so he's able to pull the mask from his face to just about croak out, "John."
"He's coming round. He's coming round! Let me get to him. I really am a doctor!"
Sherlock opens his eyes. They're still gritty. Obviously they haven't cleaned him up yet. His lips feel like sandpaper. John's face looms into his narrow view.
"Oh, God, Sherlock! I thought I'd lost you. John smashes his mouth against his, peppering him with frantic kisses. When John pulls back his mouth is rimmed with dirt.
Sherlock wanted that but he's stunned that John knew it. "How…how'd you know I'd…?"
"Did you mean it? Do you mean it?
"Mean what?" He must still be delirious, or John is, because he has no idea what John's talking about.
"We could see you. The murderer, almost-murderer, thank God, sent us a camera feed of your face."
"Yes?" If he weren't so happy to be alive and to be in John's arms he'd be frustrated with John's inability to come to the point.
"You mouthed 'I love you, John' just before you passed out. Just before we broke through and found you. Did you mean it?"
"I did?" He hadn't realized that he'd been mouthing it. Of course, he didn't know that anyone was watching either.
John looks crestfallen, as if he thinks that Sherlock was mouthing, I love you, God or some other such nonsense.
Sherlock takes a deep breath, "Of course I meant it. You were the only thing that mattered. You're all that matters."
John smiles. He slips the oxygen mask over Sherlock's mouth again and kisses his forehead before they lift the stretcher into the ambulance.