It all started with an experiment, of course. Sherlock had an unwieldy amount of equipment set up on the kitchen table and across the floor, including a small power generator and various gadgets unidentified.
Everything was going quite well until John entered to put on the kettle. There was less room to manoeuvre than normal so it shouldn't have come as a shock when he crashed into Sherlock and they sprawled across the table, John on top. But it did. A literal shock.
Luckily, Sherlock had actually built a safety into the electrical system, likely due to the last mishap. When the current ceased its flow through their bodies, John tried to push himself to standing but was hampered by the weight atop him.
Wait. Didn't I fall on top of Sherlock?
The weight lifted from his back and he stood his full height. He was viewing the world from a slightly different angle. Worse, he turned and looked down at himself.
John's mind raced. Raced!
Experiment. The kitchen needs cleaned. Accident. Is London always this noisy? Switched. The colours are so bright. Fuck. Hungry. Does the man never eat?
John clasped his head, Sherlock's head, in both of his hands and squeezed in an effort to slow his thoughts. "Stop. Stop. Stop!" He sounded just like Sherlock when he commanded silence at a crime scene, only more desperate.
Across from him, Sherlock stood, stunned. His mind felt sluggish as he tried to process the events that had just transpired. He blinked slowly as he peered at himself. What? He looked down and saw John's body. Piecing together the facts was painfully difficult but he eventually figured it out. John knocked us into the experiment and somehow we switched bodies.
Sherlock noticed John's distress. "John? What's wrong?"
A shaky baritone responded. "Too much! In my head. Thoughts swirling." John squeezed his eyes shut. "How can you stand this?"
Sherlock looked at John and after a moment understood. "Oh, John." His voice was full of understanding and sadness. "I couldn't always. Remember, the cocaine?" He knew that he wasn't being very helpful but he couldn't think. There was a strange tightness in his chest just knowing what his friend was going through. "Concentrate, John. Tell me about... the bones in the human hand." John didn't seem to hear him so Sherlock repeated the command.
Finally, Sherlock's words penetrated the mental cacophony that was raging within his head. John tried to block everything else out and concentrate, he was partially successful but the basic knowledge that he was trying to call up escaped him. It felt like he had taken a bad step and fallen flat on his face. Instantly, John was overwhelmed once again by a riot of sensory input and the accompanying thoughts that raced wildly in his head.
"Can't think properly," the doctor gasped out. His hands were now pulling at the curly hair beneath his fingers and his face was twisted in distress.
Sherlock felt a large lump form in his throat. It physically hurt to see John in such distress. He simply had to find a way to help his friend. The detective tried to remember the tricks that he had used in the past to calm his overwrought mind but the information was beyond his recall. He had tucked it away in his Mind Palace and, try as he might, that structure was beyond his reach. With that realization, a thought clicked into place. His Mind Palace was lost to him and John's medical knowledge might very well be lost to the doctor. They were going to make a fine pair.
Tears threatened to overcome the detective as he realized there was no hope of reproducing the circumstances that had resulted in the switching of their bodies. It was the pitiful mewling from John that pulled him out of himself and into action.
Sherlock decided to do for John what John would have done for him. He couldn't do much about John's racing thoughts, but he could help curb the influx of sensory information. On the occasions that gave in to his bodies needs and slept, he often employed ear plugs to filter out the sounds of London. With a pang of regret, he left John to his own devices to retrieve the ear plugs from his room. On the way, he remembered that the doctor used a menthol rub when the man became congested. Sherlock thought that that might work to inhibit his olfactory senses so he made the diversion to the loo to retrieve that as well. Fleetingly, the thought occurred to him that simple knowledge had made the transfer along with personality so at least they weren't relegated to the state of infants.
When he had returned to the kitchen, John seemed to be in an even worse state. The other man had collapsed onto the floor and was rocking wildly while pulling at his hair.
Sherlock reached tentatively to touch John on the shoulder. "John, I need you to do what I say." The doctor looked up at him through bewildered silver eyes. The confusion that Sherlock saw there made his heart ache in a way in which he was not accustomed. He fought through the onslaught of sentiment and spoke again. "Take my hand and come with me." He held out his hand, waiting for John to take it.
After a moment's hesitation, John did as Sherlock had instructed. He followed Sherlock's lead. When the detective pressed down on his shoulders, John almost flinched away but allowed himself to be seated in his customary chair.
Talking in a soothing tone of voice, Sherlock explained what he was going to do. "There's too much data coming in for you to process. I'm going to help you block some of it out. Just let me work and try to empty your mind. I know it's almost impossible, but try." John nodded dazedly and Sherlock took that as his cue to begin.
With exaggerated care, Sherlock put the earplugs in place. Next, he swept a line of the menthol rub above John's upper lip. After a moment's though, the detective retrieved his scarf and tied it gently around the doctor's eyes. Slowly, John began to calm, but not enough. Sherlock was growing frustrated with himself. His friend was still in distress and he hadn't been able to solve the problem completely. What else, he wondered, was there for him to do?
Sherlock had a moment's insight. When he was at his worst, he often perched on his chair, knees to chest, and rocked to soothe himself. Perhaps that would help. His voice would be muted by the earplugs, but that was fine, John would still be able to hear hm. "This may feel strange, but I need you to pull your legs up to your chest. Like I always sit. Can you do that John?" His question was answered by a low whine. Sherlock decided to help physically, he bent and took John's feet in hand and started lifting them. When he did, John moved into action and curled into the vulture-like for that Sherlock so often took. "Wrap your arms around your knees." John complied. Almost immediately, he began rocking again.
Standing, Sherlock found himself wiping away tears from his eyes. He moved around to the back of the chair, facing the kitchen so that John couldn't see the emotional state that he was in, not that John was in any state to notice anything at the moment.
The low keening sound that started coming from John caused Sherlock to turn instantly back to face the other man. Without realising what he was doing, the detective started carding his hands through John's hair. Slowly, the doctor's rocking ceased and he leaned into Sherlock's ministrations. It appeared to the detective that a moment's respite had been achieved. For that much, he was grateful. What was to come was beyond his ability to ponder.
