Disclaimer: Dolye, Moffat and Gatiss are the masters, I just play ^_^

A/N: Unrelated to my other stories. An AU take on the lab scene from Hounds of Baskerville. Any recognizable parts come from the episode. Thanks to Ariane De Vere's transcript of the episode on her livejournal; it was very useful, so I thought it would be appropriate to credit her for that.

Ever since I saw the episode I got to thinking about John's reaction to the drug. If, when they were back in the Hollow, Sherlock confused Frankland for Moriarty for just a moment, projecting his fears unto him, shouldn't John have had a similar reaction in the lab? In the first episode he was having dreams about the war, so it's clear it's a big deal, so I figure, even though he wasn't afraid and he craved the action, it must still have been traumatic to some level. And that's where this story came from. I think I've read another fic that is similar, but not quite, so I hope this is interesting and different!

Afghanistan in Baskerville

The lights were flashing all around him, and the blaring klaxon resounded loud and deep in his mind, turning into the rattling sounds of bombs falling. Gunfire noise quickly followed, making the laboratory shift into the desert sands of Afghanistan. It was all around him, the dirt, the sweat and blood, and bullets and the explosions going off in every direction. And screaming; screaming and shouting and yelling everywhere, it wouldn't stop.

It's not real! John told himself, It can't be real, it can't be real, he repeated over and over.

Blinking hard, his vision shifted between the empty lab and Afghanistan, while his heart pounded increasingly faster.

John ran from one end of the lab to another, forcing himself to remember the layout of the place, trying to ignore the crumbling buildings, the shouted orders, and the bodies lying on the side of the streets that couldn't possibly be there.

Taking out his phone, he quickly dialed Sherlock's number. He needed help; his rational mind told him that he was slipping, that he must be experiencing some sort of post-traumatic crisis, although he couldn't understand what had brought it on.

Sherlock's phone rang and rang but the detective wasn't picking up, and John was finding it increasingly difficult to distinguish between what he knew must be reality, and what looked like reality. People were screaming for him, calling for his help, but they couldn't be, his mind told him, they couldn't be calling him. He was back in England, he wasn't there, it wasn't real, but it was.. it was here.

Blindly John made his way across the lab to where he knew the other door must have been. He memorized floor plans instantly, thanks to his military training, so he was able to find the other door relatively easily. Now the sounds were becoming more real, he could hear a pattering resounding across the lab.

"Oh sh.." I've gone mad, this can't be happening. A growl joined the pattering noises, intensifying the bullet fire and the bombs falling in John's mind. His heart was racing painfully in his chest, and his breathing was becoming ever more erratic.

Without realizing it, John made his way to one of the cages in the room, whether to hide from his own mind, or to hide from the insurgents that are chasing him, he wasn't sure. He could hear the yells of 'Captain Watson, take the left flank!', and he wanted to follow the orders. He could even almost feel the weight of the riffle in his arms and the medical pack slung on his back.

The growls sounded like trucks rumbling among the debris and like the crumbling buildings falling all around him. The air became thick with dust and sand, making it difficult to breathe.

Suddenly his phone rang, his real phone in England. John scrambled in his pocket for it, bringing it out on trembling hands. He could barely see the device in his hands; it kept becoming a walkie-talkie, although he knew it must be Sherlock.

His breath was coming out in pants and gasps, and he was trying to control it so that he didn't sound like a complete idiot. What was happening to him? John struggled to understand.

"Sherlock! Help me.. get me out of here, please." John closed his eyes, attempting to shut down the war, make it go away, but he could hear them moving outside, soldiers and insurgents, running and screaming, just outside his cage.

"Where are you?" Sherlock's voice sounded in his ear, almost making him cry out in relief. Softly he repeated his plea, "Get me out, Sherlock. You have got to get me out. I'm in the big lab; the first lab that we saw." he said, even though the lab was barely there at all. The sands of Afghanistan were taking him away and he couldn't stop them.

John breathed heavily, trying to block the noises, trying to keep from crying out in reply to the calls he's hearing. He clamped a hand over his mouth, and he heard Sherlock's voice over the phone calling his name. At least, he thought it was Sherlock. It must be, the soldiers wouldn't be calling him by his first name, so it must be Sherlock.

"Now, Sherlock. Please." he barely whispered.

"All right, I'll find you. Keep talking."

"I can't." John's voice sounded like a whimper; he was going insane and he couldn't stop it. "You don't understand." His words came out in gasps. He knew that if he kept taking it was only a matter of time before he started yelling orders and calling out to people who had been dead for almost a year now.

"What are you seeing?" Sherlock's question made him wonder whether the detective knew what's happening. Has he deduced that I'm in some sort of PTSD nightmare?

But now it was intensifying, the sounds and the explosions, and John could feel the heat of the sun bearing down on his exposed neck, and he could smell the scent of gunpowder and death all around him. But John didn't want to tell that to Sherlock; if he admitted what he was seeing it might succeed in taking him away; he could lose himself in there.

The hand holding the phone was shaking violently and John acknowledged somewhere in the back of his mind that he was hyperventilating.

"John? What can you see?" Sherlock repeated the question.

A whimper escaped John's lips. "I can't. Just get me out,…" then reluctantly, he added softly, "they're here, Sherlock. I can hear it all, it's all around me, I can't make them stop, please help me." Never, not even in his worst nightmares had he experienced such a vivid vision of the war. It was overpowering him, enveloping him completely.

"Stay calm, stay calm. Can you see it?" It? What was the detective talking about? Couldn't he understand?

Suddenly John opened his eyes again, his vision shifting between the battle field and the laboratory. But when he looked at the tarpaulin that covered the cage he was hiding in, and he saw the shadows of men walking on the other side. What is real? John's mind screamed.

"No, no, no, no, no, please, no." John whispered into the phone, over and over like a mantra.

It was everywhere, the grittiness, the overpowering smell, the relentless screams and shouts and things exploding and fracturing all around.

He was about to leap out from his hiding place, when a young soldier appeared in front of him. Without a second thought, John jumped out of his hiding place and at the young man, pushing his head down in the process to protect him from the bullets flying all around them.

Pulling him forcefully, he ran them both to the side of a fallen wall, where he could take stock of the young soldier. He recognized him; it was Sgt. Matthews, largely inexperienced, but with a naïve eagerness to serve. The boy had been injured; his left leg had been pierced by a bullet still lodged in his thigh, just above the knee.

John rested him against the wall, quickly pressing his hands unto the wound, trying to stem the flow of blood seeping through his fingers.

"Don't worry, sergeant, you're going to be alright. You'll be back in action before you know it."

John placed his riffle on the ground, deftly unshouldering his medical bag and pulling out bandages to wrap up Sgt. Matthews' bullet wound. He spared a glance around him to make sure no enemies were sneaking behind him.

In front of him Matthews was breathing hard and his skin looked pale. The boy was clearly going into shock.

"Stay with me, Matthews, everything's going to be alright, you hear me? I'm going to wrap this up, and then I'm going to get you to base camp where we'll take this bullet out of you and you'll get a nice little souvenir."

John was just halfway through wrapping the tourniquet around the young soldier's leg when he heard a gun cock behind him. His heart jumped to his mouth as he glanced behind and found himself face to face with the barrel of a gun.

The insurgent spoke to him quickly in a language he barely understood. John had been taking classes at the base, but he couldn't follow everything his enemy was saying now.

Raising his hands slowly, John stated as clearly as he could, "I'm a doctor." He pointed to the red cross on his medical bag, "Doctor." He repeated, hoping the enemy soldier would not shoot them both then and there.

His hopes were shattered when, without a second word, the man shot him straight in the shoulder.

Pain exploded violently around John, his body taking the brunt force of the bullet and making him fall backwards hard against the ground. He needed to help out Sgt. Matthews, but he couldn't put two thoughts together. He could barely control the scream that rose to his throat.

John's eyes were clenched tightly, the pain blossoming from his shoulder and all across his chest was blinding, but he could tell he was being shaken by someone. Someone was holding him and shaking him, calling his name over and over, and the desert sands, the explosions and the screams were fading into the back of his mind.

As the doctor hesitantly opened his eyes, he discovered Sherlock Holmes looking down at him, an expression of worry and borderline panic written on his face.

On Sherlock's part, he was beyond shaken. What had begun as an experiment had gone so awry as to be considered an utter disaster.

When he arrived at the lab and opened up the cage John had hid in, the doctor had leapt up at him, manhandled him into a crouch and pulled them both against one of the lab's desks. Catching John's eyes, Sherlock had seen the dilated pupils staring at things that obviously weren't there at all. That this was not the reaction Sherlock had been expecting was an understatement.

He had quickly caught on to what was happening; it didn't take a detective genius to realize that John was trapped in some sort of post-traumatic war scenario, and Sherlock cursed himself for not considering this possibility before. Brilliant Sherlock, give the veteran army doctor who got shot in the war a paranoia-inducing hallucinogenic drug!

John had pushed him roughly against the side of the desk, his hands moving over his body in quick examination, before pressing hard on his left leg. Sherlock bit back a yelp as John's fingers clamped painfully tight around his thigh.

"John?... John!" Sherlock had placed his hands on the doctor's shoulders, trying to snap him back to reality, but John simply called him "Matthews" and continued administering first aid. Sherlock saw as John went through all sorts of motions, probably taking a back pack off that he would have been carrying, and taking out supplies that were all in his imagination.

"John! It's not real! Listen to me! You've been drugged! None of this is real. Wake up!"

But John hadn't heard him, instead the doctor had continued going through the motions of wrapping up his leg, while offering kind and comforting words. If Sherlock had ever had any inclinations or desires to see John in action, this most certainly curbed all those wishes. John moved with frightening professionalism and practice, and Sherlock was almost stunned by it.

Occasionally John had glanced back or flinched, but at what Sherlock hadn't been able to determine, although he could imagine what John might have been seeing and hearing in his drug-addled state.

Just as Sherlock was trying to determine how to best snap the doctor back to reality, John's hands stilled and he slowly turned in his crouch to look at some invisible assailant behind him. His hands went up in a nonthreatening stance, and he calmly stated "I'm a doctor", pointing to the floor beside him and back at Sherlock. "Doctor" John repeated, and Sherlock could hear the pleading tone in his voice.

"John?" He was just about to reach out his hand to once again try to bring the doctor back to reality, when John's body unexpectedly twisted sharply to his right, falling backwards hard against the floor.

A strangled scream had escaped the doctor's lips, and Sherlock sprung to his side as John's hand clutched his own shoulder in agony, his body writhing at the perceived pain.

Oh my God, this is when he got shot! Sherlock quickly grabbed John, placing his hand on his other shoulder and avoiding his 'injured' one to prevent sending John deeper into his hallucination. John's thrashing continued, his teeth grinding as he threw his head backwards.

"John! John! Wake up! It's not real! Look at me! You're safe, you're alright!" he shouted at the man.

When the doctor's eyes snapped open, Sherlock breathed a sigh of relief, seeing John's eyes focus on his face and not on some other imagined nightmare.

"You're alright" he repeated.

John stared at Sherlock with wide eyes then turned his head from side to side, seeing that he was back in the lab. Is it over? He wondered, Am I back for real now? He sincerely hoped so; that had been the most terrifying experience he'd ever gone through. It had been so very real. Why had that happened?

John tried to sit up, but phantom pain shot up his right arm, bursting blindingly at it reached his shoulder.

Another strangled cry escaped his lips, which he suppressed down to a soft whimper, as he collapsed back against the floor.

Quickly Sherlock's hands were there steading him up, helping him sit with his back against the lab desk.

Sherlock noted how John's left hand clenched around his shoulder, as though the bullet wound there was still fresh.

"Sh..Sherlock… I.. oh my God.. I.. I don't know what just.. I.." his breathing was still erratic, and his eyes looked everywhere except at Sherlock's face.

"Shh, John, it's alright. You're safe."

John closed his eyes and shook his head.

"I think I'm going mad, Sherlock. I was.. I was back there.. but it was so real.. and I knew it couldn't be real… but I couldn't stop it." John's eyes opened suddenly, staring at Sherlock with so much intensity that it made the younger man's chest constrict.

"No, no, you're not mad. John listen to me, you're not mad. You've been drugged, that's all."

"What? I couldn't have been… when? how?"

Sherlock noticed how John's right hand kept trembling involuntarily, unperceived by the doctor, and he cursed himself once again for his recklessness.

"We've all been drugged. That's how I saw the hound last night, and that's how you saw the war just now. You're not losing it."

John was still breathing heavily, but he now rested his head against the side of the deck, and focused on regaining control of himself.

"Can you walk."

"What?" John looked at him confused for a moment. "Oh, yeah, yes, of course." He made as to get up, holding on to the side of the desk to prop himself up, but the moment he put his weight on his left leg, it gave out from under him, almost sending him toppling down if Sherlock hadn't been there to catch him.

John let out another cry as his leg throbbed painfully.

"Oh crap, not again." He whispered, as he tried to put his weight back on it.

Sherlock's arms shifted around him, holding him tighter and more upright.

"John, you're alright. Just focus, we need to go put this ghost of Baskerville to rest. Come, you're fine." Sherlock knew he had to get John's mind away from what had just happened if he was to overcome it. Otherwise, if the doctor concentrated on driving his phantom pain away, he would only succeed in making it worse. Focusing on something else however, would help him.

Sherlock let John sit against the desk for a few more seconds, until John tentatively got up again, this time more steadily on his feet. His leg still hurt, but it was more manageable, and he knew it would probably dissipate the less he thought about it. Damned mental issues! He thought in annoyance.

Finally, he nodded to Sherlock that he was fine, and without a second glance at him, Sherlock strode out of the lab, not waiting for John to follow. Taking a deep breath, John followed him, still limping slightly, and trying to ignore the equally faint but nonetheless annoying throb in his shoulder.

As the day progressed, they discovered what HOUND stood for, they uncovered the experiments performed by Dr. Frankland, saved Henry from committing suicide, faced the hound and the hallucinogenic drug once again, and saw doctor Frankland blow himself to kingdom come.

The next day John was sitting at one of the outside tables of the Cross Keys Inn, tucking into his breakfast when Sherlock joined him. After commenting about the dog and his owners, John turned pensive and softly said,

"I'm sorry about what happened in the lab, Sherlock."

Sherlock swallowed uncomfortably.

"It wasn't your fault. Like I said, we'd all been drugged."

John remained pensive for a few more seconds before frowning, "Hang on,… the drug was in the fog, right? But I hadn't been to the Hollow. So how did I..?"

Sherlock didn't look at John as he answered, "You must have been dosed with it elsewhere, when you went to the lab, maybe. You saw those pipes – pretty ancient, leaky as a sieve; and they were carrying the gas, so ... Um, ketchup, was it, or brown ...?"

"Wait…you thought it was in the sugar."

Sherlock stilled, his eyes fixed on a point on the table. He'd known this was coming.

"You were convinced it was in the sugar. When we went back to Stapleton's lab, you were studying the sugar."

Sherlock's gaze shifted fractionally to John's eyes, then back at the table.

"It was you, wasn't it? You locked me in that bloody lab." John's voice was low, and Sherlock almost flinched as he thought back to John's reaction, the panic in his voice, the trembling limbs, the unseeing eyes trapped in a memory of a horrible place.

"It was an experiment." He replied softly, "I thought that the drug was in the sugar, so I put the sugar in your coffee, then I arranged everything with Major Barrymore" he confessed in a whisper.

"I was terrified, Sherlock. I was scared to death. I thought I was there again, I.. I couldn't tell what was real and what wasn't. I.. I thought I was going mad."

"Yes, well, that is what the drug was meant to do; extreme paranoia and hallucinations. I thought you would see the hound, like I did. I even told you it glowed to that you would see it that way. I didn't think your mind would provide an entirely different hallucination. In retrospect, it was… foolish of me… I'm sorry." Sherlock whispered the last part, refusing to look in John's direction as he said them.

John regarded Sherlock.

"It scared you, didn't it?" he asked softly.

"What?" Sherlock's head turned to gaze at John.

"Seeing me like that, knowing you miscalculated."

Sherlock averted his eyes once again. "It… it's not something I would care to repeat." Seeing his friend, the only person he considered a 'friend', lost within a traumatic vision, crying out in pain and trying to defend himself against imagined enemies futilely, and knowing he'd caused it had frightened Sherlock.

"It won't happen again."

John sighed and looked back at his plate, shoving a couple of bites into his mouth.

Sherlock remained silent for a few more seconds, before asking something that had been nagging at his mind since the events in the lab.

"Did he make it? Matthews?"

John placed his fork on the plate slowly, taking a deep breath before answering. His eyes had a far-off look.

"No."

The detective remained still, watching John and waiting for him to continue. When the doctor didn't, he prodded him gently.

"What happened?"

John knew Sherlock had probably deduced from his movements what had happened the day he got shot in Afghanistan; that he had been trying to save the young soldier, that he had been ambushed and shot.

With a deep breath, John answered. "He got shot. The guy that shot me shot him too, point blank, straight through his heart." John took another calming breath, while Sherlock remained immobile watching. "I told him he would be alright, that I would get him back, save his leg and give him a nice souvenir to take home. I told him, Sherlock."

"John, you couldn't have known. You did everything you could. It's not your fault you were ambushed, or that your enemy decided shooting two unarmed men, one a doctor and the other a wounded man, was right."

"He was just a boy." the doctor whispered desperately. "And I couldn't save him because I couldn't act beyond my pain. If I had reacted differently, if I had been stronger I might have been able to fight him off."

Sherlock's eyes narrowed, "You were shot. You tried to save him, once by giving him medical aid, and again by defending him against the enemy soldier."

"I know, I know that. I'm not an idiot, Sherlock. I'm not just a doctor, I'm also a soldier. I know how war works. It doesn't make me feel any less lousy."

Sherlock nodded in understanding, before frowning again.

"He was… he had been shot in his left leg." he said, remembering John's hands frantically applying pressure to his thigh.

John scoffed, "Yeah, you've figured that out then. 'Survivor's Guilt' my therapist called it."

Sherlock nodded again; he had learned more about John than he thought he would, but he genuinely wished he had learned it without having caused John to relive such a traumatic event. A thought suddenly occurred to Sherlock. He knew John's psychosomatic pains tended to go away when he was in dangerous situations, the adrenaline and the thrill of combat holding his psychological issues at bay. Now he had discovered that his psychosomatic limp came specifically from the comrade he had been unable to save the day he got shot. Did that mean that John's need for danger came from a subconscious need to continually punish himself or make up for what had happened, more than just for the thrill of the chase?

"John, is that why you love danger?"

"What do you mean?" John frowned and Sherlock explained his train of thought.

The doctor sighed and looked back down at his almost empty plate. "No, at least not entirely, I hope. I may not be a trained psychologist, but I did study it a little during my medical degree, so I considered that possibility soon after we met. But I was an army doctor long before I got shot and long before I met Sgt. Matthews, and I craved the adrenaline back then too. So if you're worried that you're enabling a mental patient by letting me tag along on your adventures, think again."

"Nonsense, if anyone's a mental patient in this relationship, it's me." Sherlock said dismissively. He was satisfied with John's answer, at least for now. He would archive it for deeper consideration later, but for now Sherlock got up from the table.

"Where are you going?" said John while turning, following Sherlock's gaze to see Gary on the other side of the patio attending to two other customers.

"Won't be a minute. Gotta see a man about a dog."

John shook his head, picked up his mug and sipped at his coffee. Sherlock Holmes was going to be the death of him, but now, perhaps, he would be a bit more self-conscious about his actions and their effects. He could only wish.

The End

^_^ Let me know whether that was any good. All the best, AR