Don't faint. He clenched his teeth and found himself fumbling blindly to brace himself against the countertop. Don't, god, don't…If ever there was a time for mind over matter, for sheer force of will… He blanched, overwhelmed with nausea. No use.

He did not register the tapping of footsteps on the stairs, the murmur of "Sherlock?" over his shoulder; he was reeling, falling into thick, roiling blackness.

He would certainly have lost consciousness, would have fallen, maybe bled out, maybe died silently here, had the sudden buzz and snap of electricity not ripped a primal, agonized scream from John's throat, throwing him to the floor where he convulsed helplessly, just a few steps from the detective.

That scream – not a shout, but a true, wretched, irrepressible scream – swept the swirling colours from inside his eyes and anchored him, firm as concrete, in the moment, in the searing pain. He reached beneath his jacket and pressed his left hand as hard as he could against the sodden tear in his shirt. Blood seeped between his fingers, and a thick rivulet had already reached his hip. It didn't matter, it wasn't important now. He turned.

Adrienne Van Orden's dark, cold eyes met his gaze, the boy's awareness of his own position of power giving them weight, depth, authority. He was crouched over John's supine form, and he made absolutely sure that Sherlock was watching as he pulled up the dazed doctor's jumper and undershirt, exposing his bare stomach, and pressed the cold metal teeth of a stun gun to his diaphragm. His pale mouth twitched as he glanced down at his writhing, semiconscious victim, then, very deliberately, pressed the trigger again.

The gun clicked loudly and every muscle in John's body pulled beyond taut, back arched, chest expanded, as another violent cry escaped his gasping mouth.

"Stop it!" Sherlock roared, trying to take a step closer, but finding that his trembling legs wouldn't quite obey him. With his right hand he fumbled to reach his pocket, his unsteady fingers closing on the grip of John's pistol.

"I wouldn't do that," Adrienne cooed, releasing the trigger and allowing John's still-twitching body to slump to the tile floor. He turned slightly to show Sherlock his other hand, which held a blood-streaked kitchen knife. The detective bristled before realizing that it was his own blood tingeing the metal, not John's. The boy adjusted his grip, then pressed the blade firmly to John's throat. "Your hands are unsteady," he confirmed, eyes sweeping over the detective's arm. "Sure, you could shoot me, but odds are pretty good that I'd have a conscious second or two to give this one a little press…" he forced the blade harder against John's flesh, drawing a thin line of blood, "or hit the zapper," he thumbed the trigger demonstrably, "and if he twitches like that again I'll almost certainly slice him open, whether I intend to or not."

Sherlock froze, but his hand remained defiantly on the Sig.

"Oh, and the floor's real tile, not linoleum. He hit his head pretty hard when he fell, so I doubt he'll be snapping up to overpower me. I mean, I know I'm smaller, but…" he gave John's leg a little kick, provoking only a soft groan and a vacant turn of the doctor's head.

"Played sick, I suppose? Convinced your mother to leave without you." Sherlock assumed. He felt himself leaning forward slightly, and fought to straighten up, but god, the pain in his side was immense…even his breathing was growing laboured.

He shrugged, "not difficult, she's not stupid enough to argue with me."

Sherlock tried to swallow, but nothing went down. "What do you intend me to do?" He asked, his voice shallow and unsteady, even to his own ears.

Adrienne grimaced. Without hesitation, he lessened the pressure of the knife on John's throat and pressed the stun gun again, and John convulsed as dramatically as before, eyes squeezed shut, hands clenched, but his cry of pain was now hardly a moan, half choked by his raw throat. As he went limp this time, Sherlock saw blood oozing slowly from his nose and the corner of his mouth. Adrienne was clearly enjoying it, his eyes glittered as he watched the doctor fight to draw breath. "You have a few options," the boy explained, "the best of which would be to run. Go for help, because you don't have long now, Mr. Holmes. You're losing blood fast." He smiled and tapped the knife casually on John's skin, leaving a few shallow nicks. "Basically, three: first, you run, get the police, save yourself, present what you have against me and solve the case, and I kill John Watson. Second, you can shoot me, exposing me, but making a murderer of yourself, and I kill John Watson. Third, you can stand there like an idiot until you bleed out, I get off free as a bird, spin some story about defending myself, and I kill John Watson."

"So zero options, really," Sherlock surmised, his voice catching slightly now.

"I disagree. Two out of three, you solve the case and you live. It's not half bad, really." He thumbed the trigger again, clearly itching to zap his victim again. Instead, he carved a few more deep lines into John's jaw. Sherlock's chest quivered, and not from the stab wound. The doctor didn't so much as flinch at the bite of the knife, and his rapid breaths looked strained, erratic. Sherlock knew that with each successive shock, the likelihood of ventricular fibrillation – and inherently of heart failure - increased exponentially, and the stun gun was undoubtedly at its highest setting. John had been shocked three times now, all of them drawn out over several seconds. How strong was his heart?

In spite of his tremulous hand and obviously weak grip, he drew the pistol from his pocket and levelled it until Adrienne was staring down the shaking barrel. Blood had reached his right shoe now, he could feel it, sticky and cooling, and he heard it drip-dripping intermittently on the tile floor. He estimated quickly that about half a pint now soaked his skin and clothes, but the wound wasn't wide, it was deep. It had almost certainly punctured his liver, and there must be internal bleeding as well. It had been about three minutes. He calculated that had perhaps fifteen more – if he was lucky, if he stayed conscious, if he kept pressure on the wound – before he was beyond saving. Something decisive needed to be done. Soon.

The boy raised his eyebrow and repositioned the knife, jabbing the tip directly into John's carotid, creating a divot in the soft flesh of his neck. "I was hoping you wouldn't go for option two," he admitted.

Keep him talking. "What did he promise you?" Sherlock panted, "money? Power? A bloodbath, what? You knew it wasn't about the grant and the school, you've known it for months. They aren't even real. What was it then?"

Adrienne smiled that pale, mirthless, un-childlike smile. "He promised me everything. The whole big, bad world, Mr. Holmes. And unlike any other person on earth, he can give it to me. Him and him alone. He understands me. Do you know what that's like?" The boy's eyes were wide with fervour, with admiration, with pain. "Do you have any idea what it's like to have people you don't even know telling you how you should be thinking, how you should be feeling, how there's something terribly, terribly wrong with you?" A deep red pearl of blood welled at the knife point, then dripped from John's still throat. "Until finally someone, a complete stranger, comes to you out of nowhere and tells you that you're valuable, that you're special, that you matter. A stranger sees you for what you really are when the people around you only see a freak. Do you know what that's like, Mr. Holmes?"

Sherlock's icy grip tightened on the trigger. He could feel his own weak pulse in his fingertip.

"You've cut yourself down to options two and three," he noticed, his voice descending from its fanatical pitch, "you couldn't run now if you tried, I could easily overtake you and stab you again before you reached the door. And this one certainly isn't going anywhere." He exemplified this by pressing the knife a fraction harder, drawing another dark droplet of blood from John's skin. The doctor didn't stir, gave no indication that he felt anything, but through the blur creeping across the corner of his vision, Sherlock thought he saw the glimmer of John's eyes opening just a crack.

"You or me, Mr. Holmes," Adrienne reminded him. "Never mind Dr. Watson here, it's you or me."

Once, in basic training, John had gotten…what was the technical term? Oh yeah, "the living shit zapped out of him" when he had accidentally laid his hand on a high-voltage electric fence. It hadn't knocked him out or anything, just made his ears ring and his hand glow an angry red for a few hours. He remembered what a friend of his had said that night as he had described it. "Electrocution isn't technically pain, you know. It tricks your brain, the synapses and stuff, but it's just a nerve overload, like when your house has a power surge." He had raised his eyebrows doubtfully at the time and vowed that he would remember to look that up. He had forgotten about it as soon as the tingling in his hands had diminished.

He knew now that it was bollocks, because he knew what pain felt like, and Christ, he was in pain now. In spite of being somehow numb everywhere, from the inside of his nose to his kneecaps, every conceivable inch of him was lit up like Christmas with reeling, pounding, burning, nauseating pain, and he couldn't care less what it technically was, because he was fairly sure he was dying from it. He was vaguely aware that there was a knife to his throat, likewise that he probably had at least a mild concussion, but it all seemed very trifling. Regardless of what the demon child did to him, he couldn't possibly be in a shred more agony than he was in already.

Wrong.

The boy pressed the trigger again, and for a blissful fraction of a second he thought he was going to black out, but a tough-as-nails constitution didn't always serve him well, it seemed, because he held on. There was liquid in his throat. He choked, but his chest was too numb, too stiff to cough it out, forcing him to gasp for air through the burn of fluid in his lungs.

Sherlock, god, Sherlock...please. His tongue was like a heavy wad of marshmallow, and he found that he could no more call out for Sherlock than he could fight the kid off himself.

But where was Sherlock? Why wasn't he doing something? Sherlock wouldn't let him lie here suffering like this, he would never...

Unless…

It seemed, in spite of the truly pitiful state his body was in, he could still feel panic, and the insistent shove of adrenaline that came with it. He pried his burning eyes open, just a sliver, and even in the near perfect darkness, even through the dizziness and the half-lucid haze, he saw the way Sherlock's shadowy figure stood, bent heavily, clutching at his abdomen. He saw the dark pool of blood at his feet and the gun trembling in his hand. He couldn't turn his head to see the boy, but he could feel his posture based on the two points of metal, one cool, one burning hot, pressed against his skin.

He was losing focus rapidly, and he had only the most tenuous control of trembling his body, but he had to do something. One of them had to.

Sherlock was no longer sure that he even had the strength to pull the trigger if it came to that. His hand was numb. Two and a half pints now, he guessed? He could lose four, forty percent, and still live, with aggressive medical care, but lucidity only held out for about two pints, usually. This was it. Did he dare take the shot? He wasn't even sure he was aiming at Adrienne anymore. His vision was going, and going fast.

This is it. Dying was the only word for it. He was dying, and he was letting John die. Take the shot. At least the boy dies too. That won't fix it, though. Won't save him, wouldn't save either of us. He wondered if the boy's hand would really twitch hard enough to slit his throat. Wondered if he could even manage to hit the boy. He could hit John for Christ's sake, he could miss completely. But if he took the shot, there was some slim fraction of a chance that John would live. If he didn't, John would certainly die.

He inhaled sharply, trying for a moment of focus, trying for even a second of clarity. He had to take the shot. Had to. Now.

His finger curled, drawing the trigger back.

It took everything John had, every fraction of resolve, every ounce of that iron will to snap through the sea of agony, to regain control for just an instant.

His arm jerked forward, catching Adrienne's – the left – and in that instant of explosive movement he finally blacked out. Hearing was the last thing to go, always was. He remembered. He heard the buzz and snap of the electricity and – as though from a great distance – the sound of a pistol shot.