John also doubted that Sherlock would have developed a strange kind of humour recently, inoculating the culture mediums in morbid pictures. So this petri-dish probably wasn't one of his companion's.
John wondered where it could have come from when and a vision of Moriarty's vicious smile crossed his mind. That creep had been playing games with Sherlock that, at some point, the Consulting Detective hadn't wanted to play anymore. People's lives had been at stake or even taken. This might possibly be another of the Consulting Criminal's twisted "pleasures". The doctor's hair stood on end and he wished that, if this had anything to do with Moriarty, it would just be a threat and nothing really dangerous.
John had to interrogate his flatmate immediately if there was anything wrong with Sherlock's latest experiments and with the stubborn man himself.
John hurried to Sherlock's room and knocked at the door, all his anger suddenly gone and replaced by worry.
There was no answer from the inside.
"Sherlock, I'm coming in."
They had a silent agreement that the doors to their rooms wouldn't be locked. They would not enter the other one's room without permission, though. Since there still wasn't any reply, John pressed the door handle and opened the door slowly. He peered into the other man's room and expected to be yelled at or to be thrown out, but he only saw Sherlock curled up on his bed, not showing any reaction at all. He had his back turned to the door, so that John couldn't see his face. Sherlock seemed to be asleep and John knew that he could actually fall asleep very fast when done with an exhausting case, but there hadn't been any in the last couple of days, and his flatmate going to sleep in bright daylight was very peculiar.
"Hey, mate, you ok?"
John went over to the other side of the bed.
"Sherlock, what's wrong with you? Answer me!"
The older man shook the younger's shoulders. There was just a little moan coming from the Consulting Detective. If he had been asleep he would have woken up by his flatmate's quite strong shakes. The man on the bed seemed to be just semi-conscious, despite not being completely limp. John put his fingers to Sherlock's carotid artery and took the pulse. It was steady, yet really fast. Something was wrong!
The doctor rolled his flatmate on the back and that very moment the tall man started to tremble violently. John was startled, but reacted instinctively. He pulled his mobile from his pocket and dialled the number that he had always dreaded being forced to use. He had strict orders not to call an ambulance, if anything happened to Sherlock, since there had apparently been something in Sherlock's past that could not be taken care of in a regular hospital. John felt it had to do with his flatmate's former drug abuse, but he had never been given details. Instead, Mycroft had given John this number and instructed him to use it in case of an emergency of any kind that Sherlock was involved in.
The call was taken instantly with a meagre "Yes, John?"
"Mycroft, I need an emergency team, a toxicologist and microbiologist and whatever you have for possible bio-hazards over here immediately. There is something wrong with Sherlock. At the moment he's having a kind of seizure! Hurry up!"
Actually, John was panicking. He didn't wait for any reply, threw his phone on the nightstand and knelt on the bed. He could be sure that Mycroft would send a whole army in just a second if necessary.
John felt something creeping up his spine, something nasty and nagging and he was sure his face displayed the same expression as Sherlock's had a couple of minutes before – fear. He knew that in just a few seconds his adrenaline level would rise up to a range where fortunately he would only just be functioning and not thinking or feeling very much anymore, his parasympathetic system more or less being shut down. He took Sherlock's cushions and covered the hard edges of the nightstand with it so that his friend could not hurt his head in his seizure. The doctor tried to get hold of Sherlock's right arm and leg and when he finally managed to do so, he rolled him into a stable side position. This was just in time, because the shaking man started vomiting. John jumped from the bed without letting go of Sherlock, keeping him in position. Once again John felt his flatmate's pulse. It was far too fast and far too flat.
"No, no, no, no, Sherlock! What the hell are you doing here?! Come on, mate, calm down!"
In fact, John wasn't sure who he actually addressed with the last words, they could as well have been meant for himself. Due to his patient's violent tremor he couldn't do very much but just make sure Sherlock wouldn't fall from his bed or hurt himself otherwise.
And all of a sudden the seizure was over and Sherlock became limp.
John quickly checked his vital signs and found that the pulse had gone to the other extreme – too slow and still too flat.
The doctor thought it was safe for the moment to roll Sherlock back in order to get him out of the vomit that was soaking his bedding. He managed to roll it out from under the limp person and dumped it on the floor.
He scrutinized the younger man and was terrified by his complexion. The usual paleness had even been replaced by an unhealthy shade of grey – a deadly shade of grey; but upon checking once again on Sherlock John couldn't find a change either for the better or for the worse. The doctor, however, knew that this very slow heartbeat could easily result in cardiac arrest if it got worse. He wished that Mycroft's men would arrive very soon.
"What's wrong with you, huh? Tell me, because I can't deduce it!"
John knew he was speaking to himself, because there was no answer to be expected from an unconscious man; therefore his heart skipped a beat when he heard his best make a sound: "T…-t…" he obviously tried to say something but couldn't get the word out. He inhaled and tried again:
"Fish… smell…" was what Sherlock more or less hissed, his speech slightly above a whisper, very slurred and almost unintelligible, his eyes remaining shut.
"What are you trying to say?"
John leaned in as close to Sherlock's mouth as possible and hoped the spoken words would make some sense to him, but his friend didn't say anything more.
"Sherlock, listen! Has your current condition anything to do with the petri-dish on the kitchen table? If yes, just try to nod or tap my hand."
John slid his hand under Sherlock's in case he wouldn't be able to nod and felt the faintest tap on his skin.
"Is it life-threatening?"
Another tap, not very much more than a tiny movement.
"Can you tell me what it is? Sherlock!"
Something that sounded like "Wha…" was the only thing John could understand before Sherlock went completely limp again.
Sherlock's words didn't make any sense to John. Fish, Smell, and the other fragments didn't give him a clue about the content of the petri-dish. John didn't know how much time had passed since he had made the emergency call to Mycroft. It felt like hours, although it could only be minutes. He knew that even Mycroft needed some time. Again John checked Sherlock's vital signs and sent a quick prayer to heaven that help would come soon. He was very worried about the bradycardia and his flatmate showed signs that the doctor couldn't find an explanation for. His skin was shining with sweat and, oddly enough, Sherlock was drooling. It could have been funny if the situation in general hadn't been so serious. However, after a brief moment, there was so much saliva that John rolled his friend back into the safe position on his right side to make sure he didn't choke on it. John hadn't seen this before in his medical career.
"Damn, Sherlock, either your mould has mutated into something very evil, or somebody very evil has his hands in this!" The doctor fought against the adrenaline which blocked his brain. He had to think!
What Sherlock had told him didn't make any sense, yet there had to be some! T… and wha…, fish and smell. Something smelled of fish, most likely the contents of the suspicious petri-dish. The doctor wished he had Sherlock's ability to retreat into a mind palace to search for information, to visualize things to himself in order to find a missing piece to a puzzle, in this case the missing letters to two words.
Suddenly Sherlock made a gurgling sound, which John had heard too many times before. It was the sound of death, of the last breath drawn.