It consumes your waking mind.
The thought crawls down your brain stem and out into your skin, making your wrists itch and ache like mad, and you know exactly what would make it stop.
You know just what it needs you to do.
You know your body is pleading for you to destroy it.
And you know you want to.
Even if you've decided you'll say no, when the wave hits all other thoughts become less important, less real. You begin trying to reason with your logical mind, to squirm out from under your previous decision against it.
It wouldn't be that bad...
It's just one more time...
I deserve it...
It would help me relax...
I need to get this out of the way so I can focus...
There are endless excuses. And at the time they all seem reasonable enough. If the need is bad enough, even a good counter-argument won't hold any water for you.
You just need that sweet, stinging burn.
The comfort.
The resolution.
The peace.
The sanity.
The adrenaline.
You find yourself taking out your tools, looking them over, feeling them, waiting-perhaps in hopes that the need will pass. But it doesn't, and somehow you are grateful that it hasn't.
Like an old friend hasn't left you after all.
Maybe the first time you slide the blade across the skin you're not really completely serious. It doesn't hurt, and there's hardly any blood.
But that light swipe brings back the memories of last time, hard-and the sight of that little blood makes something in your brain light up like burning gunpowder.
And then you're caught. Then you can finally breathe.
Then you press a little harder, bleed a little darker, hurt a little sharper... And before you know it, you've done just what you said you wouldn't do again. Your heart is beating harder, the back of your neck prickles...
And the guilt sets in.
'What have I done...?'
Your hand shakes a little as you wipe the blood off your blade. It all seems so obviously wrong now-why did it seem okay ten minutes ago? Why did you let yourself do that?
You're disappointed, guilty, disgusted... But at the same time, the blood is pretty.
That did feel nice.
You are calmer now.
Not as distracted.
And in some sick, twisted way, you're impressed with yourself for going as deep as you did. Horrified, but impressed.
The whole thing is confusing enough to make anybody feel ill.
And you can't seem to stop the cycle.
Sally's eyes seemed to bore holes in Sherlock's arm, even after he quickly pulled his sleeve back down and squared his shoulders. She was just as speechless as the rest of them. But at the same time, something in her stare communicated a deep fascination.
The way drivers are fascinated by a horrible, mangled traffic accident.
The way they can't stop looking.
But Sherlock was not a mangled accident, and he did not deserve to be looked at that way.
John felt he should say something.
But what?
He opened his mouth-but was caught off guard as Sherlock spoke instead, his voice surprisingly even and unaffected.
"Do you have a reason to be here, or are you just gawking? If you didn't notice, we were having a discussion. Whatever you need can wait."
Sally heard him.
She just didn't react for a moment.
Perhaps she was still processing the image of all those lines across his skin, as if each one were screaming at her. Each one an explanation in itself.
"D'you..." She still hadn't removed those prying eyes from him. "D'you cut yourself or something?"
"No, I have boxing matches with rosebushes. Get out."
She probably would have stayed, had Lestrade not given her a quiet verbal nudge toward the door.
Sherlock was extraordinarily silent after she'd gone.
A sort of silence that wasn't quite usual for him, and John could only imagine what might be going on inside his head.
"Sherlock..." John glanced at Lestrade, who was also casting glances between them, apparently at a loss as to how to be comforting. "Sherlock, are you alright?"
Something clicked.
The consulting detective was back.
He was fine, and everything was normal, and maybe all that hadn't even happened.
"Yes, of course I'm alright. I'm always alright. You two keep talking, I'll be back in a minute."