A/N - A long long time ago (like the summer!) qnadia7 asked me to write her something. I did, but never ever finished it to the point of being able to post it. Now I have... Kind of.

DISCLAIMER: Not mine, any of them. Good job too, seeing what I do to them.

Contains scenes regarding cardiac arrest (which really is NO laughing matter - don't read if you're squicky or have issues about that. (p.s. I am probably not quite up to scratch on my first aid knowledge, apologies in advance)

Chapter One

"If C is the electrolytic cell and the resistance of the coil is 4.5 times that of the wire, the total resistance ratio would–"

"I'm not even going to pretend that I want to know what you're doing."

Sherlock was used to John's interruptions. They rarely bothered him, no matter what he usually abruptly protested to the contrary. In fact, they quite often were timely pauses allowing him to reassess exactly what he was thinking and sometimes catch something he had missed in his haste.

"You don't." He stated, knowing it was entirely untrue. He could tell from the flick of John's eyes between his scrawled notes and the circuit of wires on the kitchen table.

"Good. Or maybe... not so good." John rolled his eyes. If Sherlock admitted hewouldn't want to know, it was a bad sign.

Sherlock went back to ignoring him and let his mind tick back to his calculation, "Zero point one."

John's huff interrupted him again, "Okay, what are you doing?"

"Electroconductivity of Rhodedendron Calendulaceum."

"Case?"

He nodded. Murder. Husband. Suspected wife. Garden plants sizzled from the inside out. Interesting.

"Just watch the energy bills." John took his mug of tea and wandered into the other room to leave him in peace.

Sherlock estimated he had four minutes of peace before John would return for more details. No matter what he claimed about experiments, they more often than not interested him too. No matter the subject, John was curious of the results and the processes it took to get them. Sherlock showed his acceptance of this by 'carelessly' leaving his notes lying around if he finished a study whilst John was out or asleep, and his discreet act of kindness was often rewarded by finding John at the kitchen table, poring over them while he drank a cup of tea.

This time he was wrong. It was less than three minutes (two minutes and thirty-four seconds to be precise) before John was back, "Plants conduct, I know that, but efficiently enough to kill someone? Would the root system not siphon out the electricity?"

"That is the purpose of the experiment. Also to assess the voltage and current required to pass through the plant have sufficient power to cause death to a human, after factoring out any weakening from absorption of the plant itself. It is impossible to replicate it precisely, obviously; I have no suicidal volunteer and the post-mortem has yet to determine the exact health of the victim's circulatory system, but I can garner a rough calculation."

John nodded and shifted his behind from the edge of the table. His movement propelled a couple of sheets of equations over the corner of the surface and they fluttered slowly to the floor. Sherlock had no intention of picking them up; after all, he hadn't knocked them off, even if he was closer to reach them now. He was busy, connecting his circuit to the convertor he had hooked up between a power socket and his plant.

"Oh, so I'll get that shall –" John's sarcasm was interrupted by a loud bang and Sherlock refocused on the room in time to see him land on the floor with a thump in the archway between the kitchen and living room.

Sherlock replayed the last three seconds in his head, watching John's hand groping along the floor to reach the papers, seeing him overbalance, his raised hand instinctively reaching for something to save him. He must have brushed against the charged plant.

"You idiot," he laughed, disconnecting the power supply. The laugh stopped abruptly when John didn't curse. Or get up. Or move at all. "John?"

It took a quarter of a second for him to realise the exact implications of the current John had just received, and the position he had been in. One hand in contact with the plant, one hand on the floor. The chances of the current passing through his heart were... Far too high. As was the voltage.

He flew across the kitchen, knocking over a chair, but barely noticing. Half of him expected John to sit up, joking all along, laugh at his concern, but there was nothing. He pressed the flat of two fingers against John's jugular. Then pushed upwards desperately, until he was practically digging into the cavity under his jaw. There was one desperate lonely beat, maybe two, but no real pulse. He checked his wrist, his chest, bent to listen for breathing.

Panic set in.

For some reason the first numbers his thumb pressed on the dial screen of his phone were not 999, but his brother's speed dial code.

"Brother dear?" Mycroft was smooth and sure, and Sherlock hated him. Why had he called him?

"Send me a damn ambulance. I've killed John."

"Sherlock?!" That had shocked him. He didn't think he had ever heard Mycroft's voice break like that.

"Get me one now. I know you can. I know. He's dead."

"What's happened? Are you at home?" He was calm again, but in the background Sherlock could hear him moving, opening a door, clicking buttons.

"I've electrocuted him. He's completely out. I've disconnected the supply, but there's not really any pulse , no... nothing."

"Start CPR, there's an ambulance on the way." And the line went dead.

Sherlock dropped the phone. He could remember reading a study about the chances of resuscitation on a subject whose heart had completely stopped versus a basic cardiac arrest with staggered unsteady heartbeats. He couldn't recall the results. If Mycroft was worried it only cemented the idea that this really was terrible. But he just couldn't make himself work. None of him would move, and his brain had apparently stopped ticking over. For the first time he could ever remember.

To Be Continued... Obviously.