Author's Note - Warning: Chapter ends in a tense spot. If you're not keen on cliffhanging all weekend you might want to wait for the next update. Brave climbers proceed...

Sherlock didn't come home that night, or the next, and eventually John got tired of waiting around to die.

He was sitting in his chair, idly flipping his phone around in his hand. Apart from the increasing number of dizzy spells he wasn't experiencing any debilitating symptoms yet. He had worked the past two days at the surgery as though nothing was wrong. He didn't see why not; when the poison triggered the shock-inducing reaction it would happen suddenly. There was nothing preventing him from functioning normally until that time, and god only knew he wasn't going to spend the days sitting in an empty flat waiting to keel over.

It was ironic working at a surgery full of equipment and medications and knowing none of it could help him. He'd poured over Sherlock's notes on the poison that first day, and though they were mostly haphazard chicken scratch, he'd been able to decipher them well enough to understand the basic pathophysiology.

Slowed heart rate, excessive vasodilation (widening of the blood vessels), loss of elasticity in red blood cells causing them to clump together and move sluggishly, not delivering oxygen fast enough. Fairly straightforward precursors to shock, the potentially fatal panicking and eventual failure of the body's circulatory system.

The clever part, he supposed, was that the chemicals in the poison rendered the body unresponsive to vasoactive drugs: his blood vessels wouldn't respond to vasopressors (the medications that would constrict his blood vessels and help raise his blood pressure) and his heart wouldn't respond to inotropes (the medications that would support the strength of his heartrate). Like triggering a bizarre kind of stasis in his vascular system, the poison had made it resistant to interference via any conventional methods.

The conclusion, John had grimly realised, was that Sherlock had to invent a medication to reverse a reaction from an entirely new drug on which there was no research, no data, and no information available. And he had to do it in the time it took the demand for oxygen in John's body to outweigh the supply, which could happen any moment. The slowing of the circulatory processes was gradual but the onset of shock would be sudden. Lack of oxygen. Loss of consciousness. Nothing to stop the progress of deterioration and total shut down. The impossibility of the situation was almost laughable.

So John had gone about his day seeing patients. He'd handed out the usual diagnoses and prescriptions and encouraging smiles: "You'll be fine."

He leaned back in his chair, hating the quiet stillness of the flat. He rechecked his latest texts from Molly.

He's all right. Still working. Even madder than usual if possible.

Are YOU all right? He won't tell me what's going on but I know it has to do with you.

John had thought about going down to Barts himself several times already. The chemistry was more than beyond his abilities, but that was usually the case during the many long hours they'd spent holed up in the lab, and still he'd been able to keep himself busy with menial tasks, just content to radiate companionship if nothing else.

But this time was different. John was a human time bomb with no visible clock. His presence in the lab would cause additional stress, and without being able to contribute to the science in any meaningful way he would only be a distraction.

He typed a response.

I'm fine. I know food is out of the question but make sure he drinks something occasionally.

His phone lit up just a minute later.

I know. I'm on it.

He smiled ruefully. It was comforting to know that Sherlock had such secure pillars of support in place. Between Molly, Mrs. Hudson, Lestrade, and Mycroft, he would be taken care of. He would be ok.

John stood up restlessly. If he was going to die he wanted to do something worthwhile with the time he had left. Before he could think better of it he sent a text to Mycroft.

If Sebastian Moran were convicted, could they hold him? JW

Surprisingly he received a response just a few minutes later.

Not for long. He is well connected. M

John didn't bother wondering why Mycroft hadn't asked for the reason he wanted to know. With Mycroft it was always safe to assume he already knew.

John leaned on the back of his chair, staring at the message, thinking. Moran had had Sherlock in his grasp the other night at the warehouse. But he hadn't killed him. Why? Was it possible they had let him go so he could try to save John? Some kind of test? John scoffed inwardly, it was more likely to ensure Sherlock would witness John's death. That sounded more like Moriarty. Sick mind games.

But once John was dead there would be nothing to prevent Moran from killing Sherlock too. Lestrade might be able to send him to jail, but Mycroft had just confirmed jail wouldn't hold him. He'd be back on the street soon enough, and he'd go after Sherlock.

John stuffed his phone in his pocket and went to the living room table. He flipped open his laptop. There was something he could do before he died after all.

He couldn't kill Moriarty; Moriarty was already dead. It had taken Sherlock Holmes to kill him, and it would take Sherlock Holmes to stop the aftershock too—the waves rippling through England that the consulting criminal had put in motion before he died.

But who was Moran? He was Moriarty's second in command; clever, sure, but in the end just a man. He knew it wouldn't solve all of Sherlock's problems, but it would strike a lasting blow against the opposition: the forces trying to hurt Sherlock, the ones John wouldn't be able to protect him from anymore.

Killing Moran would be the least he could do for Sherlock before he died.

Molly Hooper had just crossed the line from anxiously concerned to absolutely terrified.

She'd been working with Sherlock night and day, not fully understanding the project but following Sherlock's orders obediently: prepping chemicals, running tests, recording reactions, only going home in the early hours of the morning to get some sleep. Sherlock was still working when she'd come back seven hours later.

Sherlock often worked all night, but this was now the third day in a row and he hadn't gone home, hadn't slept, hadn't rested since he'd started.

She'd gotten next to nothing out of him about what they were doing. She knew they were working with John's blood. Considering the tests they were running on lab rats she also knew it had something to do with vasoconstriction. None of it made any sense. But even the slightest inquiry on her part was rebuffed by a demand for silence, and she'd given up trying to ask.

Molly knew Sherlock appreciated her help, but he was working like a bat out of hell and she understood that any politeness or display of gratitude (normally a struggle for him) would be entirely beyond his capabilities at this point. So she gritted her teeth and did what she was told, making excuses for missing work and only going home to sleep for a few hours at a time. Each time she arrived back at the lab it was as though Sherlock hadn't noticed she'd gone. There was no greeting, and often he was already halfway through a sentence as she walked in the door.

Billy drifted in and out, sticking around for a while to help weigh and measure chemicals. He was surprisingly handy in the lab—Molly knew he had an extensive background in making drugs—and he was actually a better than fair chemist. This, though, was out of his league. It was out of Molly's league. She expected it would be out of anyone's league if it were at the limit of Sherlock's.

It wasn't until the second day that she realised Sherlock had been intermittently snorting cocaine from the start, and that Billy had been slipping it to him on each of his visits. The only thing that kept her from slapping him across the face and dialling Lestrade immediately was the vague understanding that all of this was somehow connected to John. Based on Sherlock's manic behaviour, the fact that John hadn't appeared once in the lab, and despite John's text claiming he was fine, Molly knew there was something wrong. It was only the thought that John could be in danger that made her hold her tongue.

But it didn't prevent her from following Billy out into the corridor the next time he appeared, cornering him against the door and demanding to know why he was giving Sherlock drugs.

"Well, he asked for them, innit."

"You don't have to give them to him!" she seethed.

"Right, you try not doing something he tells you to; let me know how that goes."

Molly backed down. She knew what he meant. She felt powerless. She could refuse to help Sherlock unless he threw away the drugs, but she knew that would only mean Sherlock would tell her to go to hell and continue on his own. From what it looked like, John's life could be at stake. If Sherlock needed to use cocaine to save him, then Molly knew this was the one circumstance in which they'd all have to let it slide.

So she continued to work at his side, trying her best to stop calculating the exact amount of cocaine Sherlock was ingesting and to simply appreciate the fact that they were in a hospital, and help would be just around the corner if he overdosed.

All had gone relatively smoothly—excluding a few outbursts: failed tests that required her to shield the equipment with her body in order to keep him from smashing it—until now.

It was around six o'clock in the evening of the third day and Sherlock had been working silently, racing around the room with bloodshot eyes and hair standing up wildly: the very portrait of a mad scientist. He hadn't spoken for hours and when he did Molly had to do a double take.

"What?" she asked.

"Dej mi další podložní sklíčko," Sherlock snapped, repeating what he'd said the first time.

Molly stared at him. He was speaking a different language. "Sherlock, I can't understand you."

"Co je sakra s tebou? Neumíš anglicky?" They seemed like questions. She didn't know what he was asking. The frustration in his tone was sharp.

"What? What language is that?"

"Jsi natvrdlá? Podej mi to podělané sklíčko!" he yelled.

Molly felt panic rising in her chest. "Stop it! I don't know what you're saying!"

"Tak odejdi, pokud chceš dělat hloupou!" Sherlock strode over to where she was standing and knocked her hand out of the way.

He snatched the vial of blood and a microscope slide, swiftly using the dropper to create another film. His hands were shaking. He grabbed another vial with one of his latest solutions and she scampered out of his way as he swept over to the microscope.

Molly watched him with wide eyes. He was mad, absolutely mad. He wasn't speaking English anymore. He was swaying on his feet. He could collapse any minute.

This had gone too far. Sherlock wasn't going to be any use to John at all if he overdosed. She needed help. She needed to call someone. John was the first person that came to mind, but she looked over at Sherlock and supposed now might not be the best time to bring John in, especially if he was—well, she didn't know. Who else could she call? Sherlock would only demand more drugs from Billy, and Lestrade would probably tackle him into handcuffs.

But wait, Sherlock had a brother, didn't he? An older brother. She had met him once. He'd looked… important. He must be able to help.

In Sherlock's feverishly distracted state it was almost too easy to pinch his phone.

John walked casually into the lobby of the office building just a few blocks from Trafalgar Square. It had been easy enough to look up Moran's office, and a quick call to his secretary confirmed the time of his last appointment.

He walked straight to the lifts and pressed the button for the parking garage. Besides the button for the lobby it was the only one that didn't require a keycard to make the lift work: a trick he'd learned from Sherlock.

He walked slowly through the first row of cars, observing where the cameras were just out of the corner of his eye. He wove through the row and stepped behind a pillar. A blind spot. There was no camera facing his direction. He could get Moran as he came through the door. He checked his watch. Seven o'clock. Moran's last appointment would just be ending. He was proud of himself for having gotten so far without the genius of deduction at his side, though he wished Sherlock were with him anyway.

The plan was almost absurdly simple. But then, John knew better than most how simple it really was to kill a man. Especially if you happened not to be concerned with the consequences.

There would be no mind games. He wasn't Sherlock and Moran was no Moriarty. While a consulting detective and a consulting criminal might die a thousand deaths, he and Moran could each die once. They were two ordinary men. One real death each. The fate of all ordinary people.

He leaned back against the pillar, hand on his gun against the small of his back. He was dizzy now. He hoped the spell would clear in time to get a good shot at Moran. He only needed one good shot.

"Sherlock?" Sherlock's brother inquired when Molly rang him from the detective's phone. "This is a surprise." His voice was soft and smooth and somehow terrifying at the same time.

She was crouched in an empty room down the corridor so Sherlock wouldn't hear her. The precaution was probably unnecessary. She didn't think he had noticed she'd left.

"Oh, erm, hello, my name is Molly Hooper. I work with Sherlock, er, sometimes. I work in the morgue at Barts."

"Consider the surprise compounded," he said dryly. "What can I do for you, Miss Hooper?"

"Well, it's Sherlock. He's, erm, here at the lab. Actually he's been here for three days now and I think he's in trouble."

"What makes you think that?"

"He hasn't left the lab since Monday and he's done a shocking amount of cocaine."

"Really." The taut strain in the word might have had pain beneath it, but Molly would be embellishing if she said so. It was only one word.

"It's because of John, er, Dr. Watson—I should have said. Sherlock won't tell me what's happened, but he's trying to invent a new drug."

There was silence on the other end of the line.

"He's stopped speaking English!" she said desperately. "I think he's going to overdose."

"What language?"

"What?"

"What language is my brother speaking?"

"I have no idea! I didn't recognise it at all—"

"In that case I believe I know. Thank you for your call, Miss Hooper. I'll look into the matter."

The call ended and Molly stared at the phone. Did that mean he would help? Or what?

Fortunately it was late enough that most of the building's workers had already left. One or two stragglers walked through the parking garage and John pretended to be texting if they passed him.

Finally he heard the door to the lifts open and when he looked around the pillar it was Moran walking into the garage. He was certain. He'd memorised his picture from the web page. He was alone. Perfect.

John stepped to the side of the pillar, in plain view of Moran but careful to keep in the camera's blind spot. He supposed it didn't matter much if the security got a visual of him, since he would most likely be dead in a few days. But still, he didn't want to leave Sherlock with a mess to clean up.

John cocked the gun and Moran looked up. He smiled, a look of recognition crossing his face. He opened his mouth and John shot him through the forehead before he could say his name.

Quickly John shot the cameras blocking his path to the doors. He moved swiftly, stepping over Moran's body and punching the button for the lift. It was empty when it arrived and he hit the button for the lobby.

The receptionists had gone home, and the entrance was deserted. His footsteps echoed on the marble floor as he walked out the same way he'd come in.

"I've got it," Sherlock said slowly, staring at the results on the screen in front of him as they blurred in and out of focus. "I've solved it," he said louder. "This is it!" he shouted. "I've got it!"

He leaped up from his stool, knocking it backward. It clattered to the floor and Molly jumped away, skittering around to the other side of the worktop.

"It's the antidote! It works! Come here and look at this!" he jabbed his finger at the screen. Molly didn't move. "What the hell is wrong with you?" Sherlock yelled at her. "I told you I've solved it!"

"Congratulations."

Sherlock snapped his head up. Mycroft was standing in the doorway.

Molly edged across the room.

"Where are you going?" Sherlock demanded. She didn't respond. She slid out the door behind Mycroft.

"She can't understand you, Sherlock. Are you really not aware that we're speaking Czech now?"

Sherlock blinked at his brother, the room was swimming before him, circles and pricks of light dotted his vision. "It doesn't matter. Look, I need this antidote made immediately. Can you do it? John will die. Mycroft, I need your help."

If Mycroft was surprised by the unusual request for assistance, he didn't show it. He stepped behind the worktop, surveying seventy-two hours' worth of crazed calculations.

"Get the formula in a legible format and send the instructions to this address," Mycroft said, holding up his phone.

Sherlock had never typed faster.

"Where is John?" he asked as he hit 'send.' "He needs to get this injection as fast as possible and we have to watch him until it's ready. He could—If he's not already—" The words were sticking in his mouth. He gripped the worktop to keep from falling over.

"John is still alive."

"Where is he?"

"Have you made a list?"

Sherlock did his best to lock his eyes on his abhorrent older brother even as he blurred out of focus. His skin was buzzing. He could feel his heart beating at a pace that would have been alarming if he'd cared even slightly.

"Where is he?" he repeated slowly enough to make the threat implicit.

"The list, Sherlock." Mycroft's posture was rail straight and Sherlock knew that even if his fighting skills were superior, his detestable brother could make things more difficult than he had time for.

Sherlock reached into his jacket pocket and tossed the paper onto the worktop. Mycroft snatched it, expression unchanging as he calculated in seconds the lengthy list of grams Sherlock had jotted down with each dose. His eyes flashed from the numbers to Sherlock's face.

"Now tell me," Sherlock said through gritted teeth.

Mycroft smiled humourlessly as he folded the paper, tucking it neatly into a small notebook that he replaced within his jacket. "All that cocaine and you're still too slow." His grey eyes held Sherlock's mercilessly. "You know where he is."

"I don't have time for your games, Mycroft," Sherlock snarled. "He must be at home. Or at the surgery." Sherlock had no idea what time it was, what day it was.

"John has been given a death sentence and a minimal amount of time left to live. Do you really think he's sitting home staring at the walls?"

Sherlock reeled as he understood what Mycroft was saying, and he hated him for being right. Because he did know where John was. He knew exactly where, and he had to get to him. Now.

Sherlock ran, flinging open the doors and jumping into the waiting car, neither noticing nor caring that it was one of Mycroft's cars and not a taxi.

He shouted the address at the driver, unaware of Mycroft getting into another car behind him.

John turned onto a dark, quiet side street. He was always amazed that such a thing could exist in the centre of London. Even somewhere between Piccadilly and Westminster there were empty streets, sheltered from the noisy throngs of tourists just a few blocks over, all herding up and down the same narrow routes.

His head was spinning but he felt good. He had accomplished what he'd set out to do. He had killed Sebastian Moran—one of Moriarty's most trusted accomplices. There was now one less dangerous criminal in London trying to kill Sherlock. It was the least he could do for him before he would have to go.

He felt impossibly light, almost unaware of the pavement beneath his shoes. As a doctor, John knew the warning signs of fainting. He knew the symptoms of the poison too: hypotension, eventually hypoperfusion. His brain wasn't getting enough oxygen. He should probably sit down somewhere.

He'd walked a few blocks already; there was a main road up ahead. A black car screeched to a halt and someone leaped out. John stopped, watching the person running. Was he running toward him? It was hard to see through the fog. Though there wasn't really fog, was there?

John's skin felt numb. Spots danced on the periphery of his vision. He supposed he should have sat down. But wasn't it—? It was Sherlock running toward him. Why was he running? It didn't seem necessary. John wasn't moving. He was standing perfectly still. Or, more accurately, he was falling. He didn't realise it until Sherlock caught him.

They sank to the ground, Sherlock's arms around him. He reached up, holding on to Sherlock's jacket—where was his coat? Wasn't it cold? John didn't know; he couldn't feel; it wasn't important. He relaxed into the detective's embrace. He was tired, so tired. His vertigo made the street slant and tilt precariously beneath them.

His eyes were heavy and he struggled to look up. When he met Sherlock's eyes John felt a jolt through his body, like a spasm briefly pulling him back from the brink of sleep. For a moment he was awake again, looking up into the detective's face. And suddenly it was worth it. The dizziness, the wound, all of it. Was he wounded? He didn't feel any pain, but he must be. Why else would he be lying in the street? Why would Sherlock be here holding him like this? It didn't matter. It was worth a wound; it would have been worth many wounds to see that expression on Sherlock Holmes' face. His usual mask of cold and arrogant indifference had vanished completely, and John had a window into a depth of emotion he would have never thought possible. And it was for him, John understood in amazement. Sherlock's eyes were wet and he was looking at John like he loved him.

John swallowed. It's ok, he wanted to say because he wanted Sherlock not to hurt. But his mouth wasn't responding. The fog was settling back down, pressing in around him. I killed him for you, John wanted to tell him.

Sherlock was saying something. He couldn't hear. It didn't even sound like English.

He was so dizzy it was hard to see. He just needed to sleep. Sherlock's wiry arms were around him—the lean strength of the detective's body—it was comforting, like something he'd wanted all along.

Sherlock was holding him like he was something important, precious even, and John hated that he was just understanding now, when it was too late.

He couldn't fight sleep any longer. He felt his hand slipping down from Sherlock's chest as he lost the ability to hold on. Sherlock gripped him harder but John could barely feel it. He was vaguely aware of Sherlock's curls brushing his face as his eyes fell shut.

John was falling and Sherlock caught him but it didn't seem to matter how tightly he held him because John was still falling.

Sherlock was saying things and he had no idea what he was saying. He hoped he was telling John not to leave him, because he needed John to stay with him, to wake up, to get up. John, John—

John reached up, gripping his jacket, and his eyes searched his face in the same expression of wonderment that had made Sherlock pull him out of the Barts lab and into his flat and into his life.

John, John. Sherlock didn't know if he was thinking it or saying it or shouting it. No, John, no I caught you, see? I have you now. I solved it. I invented the antidote. I solved it. I solved it for you.

John's eyes lost their focus and his hand dropped. Sherlock tried to hold him tighter, as though he could stop him from falling. But he couldn't. Because it wasn't John's body that was falling. It was a part of John that Sherlock couldn't reach, falling away from him.

John's eyes slowly closed and Sherlock buried his face in John's neck. No, don't leave, don't leave me, John, please, I need you. Please, John, John—

And then there were hands. There were rough hands on John, maybe four, maybe fifty, trying to pull him away. Sherlock wouldn't let him go. He was yelling, yelling something, he didn't know. John was ripped out of his arms and then there were two more hands, firm on his shoulders, pulling him back, pulling him up.

Mycroft.

Mycroft was pushing him into a car, slamming the door shut. Sherlock barely heard him give the address before he blacked out.

Czech translations:

Dej mi další podložní sklíčko - Get me another slide.

Co je sakra s tebou? Neumíš anglicky? - What the hell is wrong with you? Can't you speak English?

Jsi natvrdlá? Podej mi to podělané sklíčko! - Are you stupid? Give me the fucking slide!

Tak odejdi, pokud chceš dělat hloupou! - Then leave, if you're going to be stupid.