In the intensive care unit of Southern Queen's Hospital, Noah and Ronnie finished reviewing the charts of all the patients from today's mass casualty incident. Initially, there were 11 patients on life support in the unit due to the mysterious poisoning, now only 4 remained, unconscious and unable to communicate.
"The lab report showed extremely high levels of nicotine in all the patients, perhaps they were smoking together before the conference?"
Noah proposed, knowing full well that even the heaviest smokers wouldn't show nicotine levels as high as these pathologists had, but he had no other ideas. Ronnie replied as he read through the statements he had gathered from the patients' families.
"Cigarettes have over 7000 different chemicals in them, the lab report only mentioned nicotine and nothing else, cigarettes are highly unlikely to be the cause. My bet is still on the nicotine being mixed with the carbon monoxide in those compressed gas containers."
"There's an easy way to disprove that theory."
The voice came from around the corner, it was Juliet, with Camila following close behind her. She continued.
"Camila was exposed to the gas as well, and quite a bit of it too. Didn't you two mention her carbon monoxide level was high like 21% or something? If she had breathed in enough of the gas that was released inside the room, then it makes no sense as to why she didn't go into respiratory arrest unlike the forensic pathologists. Instead, Camila recovered after a little while of oxygen therapy."
The rest of the team gave Juliet a short clap after she made her deductions, a small blush growing on her face. Camila followed up after Juliet finished.
"Since the possibilities of the low-hanging fruits of the poison being distributed through the gas, cigarettes, the tea, and the documents shared among the people who were in the room have been eliminated, we need some new ideas. Let's pool together our findings, Juliet, please."
"We've already tested the milk tea that the patients drank and the document that they held for any abnormal chemical composition, no poisons were in them. I've searched through all the belongings that were in the room, but there wasn't any food, drinks, makeup, or anything that was shared by all the victims."
Camila took out a marker and began listing everything Juliet had said on a nearby window, before she turned towards Noah and Ronnie.
"Now you two."
Ronnie gave Noah a nod before he began.
"We asked around the family members of all the patients, there weren't any events that they would have all gathered in prior to the conference, so the likelihood of the poisoning happening at some point prior to the conference is unlikely. As I've already mentioned, carbon monoxide and nicotine were the only two poisons detected in the deceased patients. We also couldn't find any puncture marks on any of the patients, the nicotine being delivered through a needle is also unlikely."
Camila wrote down a list of the ruled-out routes the poison could have been administered through and crossed them all out. Right beside that list, she started a new one and said.
"We need to start thinking of more unusual routes of exposure to the poison. I'm thinking that there could've been something distributed outside the room on the same day as the conference, maybe some candy or tissues given out at the main entrance of the university, or something that would have been used and disposed of quickly and wouldn't be found within the room. We should look out for large numbers of packaging in the trash or anywhere else."
Juliet was the next person to give a proposal.
"Maybe they had breakfast or lunch together at some point? We should ask around to see if anyone recognised them eating together at nearby restaurants. I'm sorry, my specialty is in infectious diseases, I don't know much about this stuff."
Noah the emergency medicine physician followed up after Juliet finished.
"Dermal exposure still hasn't completely been ruled out. Just because there was no singular common item that all the people in the room shared doesn't exclude the possibility of multiple objects being contaminated with high concentrations of nicotine. We should also check the surrounding facilities, handrails, tables, chairs, and anything that the participants could have touched."
Ronnie the advanced practice nurse was the last one to propose his theory.
"We should definitely check around all the labs for any experiments utilising nicotine. An accident is still possible, and remember that this incident occurred in Haucon City University, a place with several labs handling dangerous chemicals. Perhaps someone didn't take their safety protocols seriously and spread the nicotine that they were experimenting with around the university.
Camila wrote down all of their theories, on the window there were four items circled in a blue marker: gifts, catering, surface of objects, and laboratory accident. Once Camila finished writing down everything on a random window in the ICU, she stepped back and pondered for a moment before she was interrupted by her phone ringing. She picked it up, and the caller was labelled Professor Wong.
"This is Camila speaking… yeah boss? Okay, I'll go check it out, thanks. Goodbye."
Everyone gathered around Camila after she finished the call, hoping for new information that could give them a clue to solve the mystery.
"The person who just called me was the director of biomedical science, aka my boss. He just informed me that one of the victims recovered from the poisoning after receiving hyperbaric oxygen therapy at Nethersole Hospital, he's asking us to go grill him for some answers. Let's divide and conquer here, Noah, you come with me to Nethersole Hospital, Juliet and Ronnie, you two go to the university and test some of our theories we've just developed."
After hastily wiping off the scribbles on the window made by Camila with some tissues, Juliet and Ronnie nodded in response to their team leader. Noah brought Camila down to the parking lot, leading her to his car.
"By the way, Camila. Why do you need me to come with you? You just need a ride?"
Camila chuckled and shook her head as she got in the passenger seat.
"Of course not. Your specialty is in emergency medicine, right? I thought you guys specialised in solving mysteries, I mean, that's basically what differential diagnoses are, right?"
Noah began driving as the two began chatting.
"Usually it's more along the lines of figuring out what stupid thing people manage to put down their throat… or up their butt. Not exactly solving a mass murder case."
Camila brushed off what Noah said with a casual wave.
"Anyhow, asking patients questions is the job of a doctor, not a scientist like me. You'd better use this opportunity and find a breakthrough, Dr. Raymond."
As Noah pulled up into the parking lot of Nethersole Hospital, he said out loud.
"Conversation is the basis of every diagnosis, after all. Time to show off what a specialist in emergency medicine can do."
The duo got out of the car and entered Nethersole Hospital, taking the elevator up to one of the medicine wards. Inside, they find a middle-aged man scrolling on his phone while sitting upright on one of the beds.
"Good day, sir. I'm Dr. Raymond, and this is Dr. Fletcher, we are part of the university's investigative task force and we would like to ask you some questions about today's incident at Haucon City University."
The man put away his phone and shifted his posture to face the two people who had just walked towards him. There wasn't a hint of surprise on his face at the arrival of Camila and Noah.
"Ah, I've been told that they were going to send Dr. Fletcher and her colleagues to come pay me a visit. Sure, let's get this done properly. As a forensic pathologist myself, I want to know the truth just as much as all of you."
Noah asked a long series of questions, scrutinising every detail that the man could remember. Meanwhile, Camila walked around aimlessly, her mind filled with boredom, until she heard something that caught her attention.
"… so I ended up arriving a bit late after I missed the bus. Wait, now that I think of it, there was something unusual. The tea that they served tasted horrible. It was undrinkable, there had to be something wrong with it. We just decided to order take-out milk tea afterwards because it tasted so bad."
Camila jumped up and exclaimed.
"Aha! I knew there was something wrong with the tea. They got rid of it because it tasted so bad, which explains why we couldn't find it at the scene of the incident. This is almost too easy, I mean, whoever was responsible didn't even bother to cover up the terrible taste of the poison."
Noah nodded in agreement and sent a text message to Juliet and Ronnie at the university to go find the original pot of tea that the pathologists were served. The man coughed repeatedly before he continued.
"Well, you'd better get to it. Once it's confirmed that the tea was the source of the poison, it shouldn't take too long to find out who was responsible for all this. There are only so many people who could've prepared it."
Camila gathered her belongings and headed towards the door.
"Noah, stay here with the pathologist, we might need additional information from him and it would be more convenient if you remain here. I'll go back to the university to help Juliet and Ronnie operate the analysis equipment."
Camila walked out of the ward and the hospital, and took a bus back to Haucon City University, there, she linked up with Juliet and Ronnie. Ronnie informed Camila as they walked towards the biological sciences lab.
"I've found the pot of tea the pathologists were talking about. We found out the bitter tea was gotten from the kitchen in one of the restaurants inside the university, and the police are already questioning the kitchen staff."
Camila found a woman standing outside the lab, as she took out her wallet, ready to rent out the GC-MS machine, she froze.
"Hmm, what's wrong, Camila?"
Juliet inquired, to which Camila replied.
"No, this is wrong. This is a red herring, I know it. I just know it."
Ronnie raised an eyebrow at Camila's statement, asking her.
"What do you mean our most promising lead is a red herring? How do you know?"
Camila paid the rental fee to use the laboratory equipment and threw a lab coat towards Juliet.
"We were blinded by the hope for such a straightforward solution, it's a simple deduction to figure out that it's wrong. If the pathologist knew that the tea tasted terrible, that meant he also consumed some of it. However, he, unlike the rest of the victims, did not enter respiratory arrest, he only experienced carbon monoxide poisoning, evident by the fact that oxygen therapy was effective on him. The problem is unlikely to be in the tea."
Juliet facepalmed herself as Ronnie let out a sigh before he said.
"Well, let's test the sample anyway just in case. But if it's not in either of the two cups of tea, then where the heck did the nicotine come from? It makes no sense."
"Well I hope you two did your job and explored some of the other theories we had earlier, did you find anything?"
Juliet shook her head as she took out a notepad and began reading through it.
"Nope, we asked the police investigators who already searched through all the trash around the area, nothing in large enough quantity to be distributed to all 40 victims. Security footage also showed that they did not arrive at the conference together, so they didn't do anything together prior to stepping into the room. They also never left together."
Ronnie interrupted Juliet as he added on.
"None of the labs had any official records of nicotine being handled either. We swabbed pretty much everything we could, door handles, tables, chairs, and bathroom sinks. We might be able to find residues of nicotine on them, but I'm not hopeful as the severity of the nicotine poisoning is so high that I doubt dermal exposure is likely."
Camila lifted her hand onto her chin, desperately searching for any alternative theories in her mind, but she couldn't. She sighed in resignation as she pointed towards Juliet.
"You go test all the samples with gas chromatography, Juliet. I guess Ronnie and I will go back to the drawing board while you're at it."
While Juliet was busy in the lab analysing the samples they had collected, Ronnie and Camila headed towards the small restaurant inside the university grounds, where the police were slowly questioning the kitchen staff one-on-one. Camila approached one of the officers, his white uniform indicating his more senior position in contrast to the regular light blue uniforms the other officers wore.
"Officer, mind if we listen in to some of the questionings? We're from the university's investigative task force."
The officer frowned at the sight of Camila, he let out a sigh and hesitantly nodded.
"Fine, as much as I dislike your weird little team's involvement in this, I suppose you did give us this clue. Go take a seat next to the officers doing the questioning and help yourselves, just try to stay out of the way of their work."
Camila and Ronnie took a seat at a table where there were two officers and one of the kitchen staff. One of the officers asked.
"What were you doing this morning?"
"I was on dishwashing duty. It was especially busy today."
"Why was today so busy for you? None of the previous staff that we asked mentioned that."
"Well, for one there were a lot of customers today, including the people at the conference who requested a delivery of beverages. Second, a lot of customers complained about a bitter aftertaste in the tea. Since we knew that the people at the conference sent back their tea because it was too bitter, it was obvious that some of the bitter residue was left on the teacups. This meant I had to hand-wash them very thoroughly on top of my usual work, which is why I was so busy today."
The other officer noted something down on a piece of paper while Ronnie did the same on his phone, both of them interested at the mention of the bitter tea that was the current suspect in the minds of the officers. The officer who was doing the questioning continued asking.
"You mentioned the customers could taste the residue of the bitter tea served at the conference, right? In that case, did any of them complain about feeling sick?"
The staff member shook his head, to which Camila narrowed her eyes. After the officer's partner finished noting this information down, he continued the questioning.
"Let's get into the main topic, who prepared the pots of bitter tea?"
The staff member thought for a long while, trying to access every last fragment of his memory, before he finally answered.
"It was Emma, she made the tea. However, she forgot and ended up delivering them way too late after the conference had already started when they should've been delivered before the guests arrived. Our boss got pretty mad at her for that."
At this point, Camila got a text message from Juliet, and she got up from her seat, soon followed by a shocked Ronnie. She walked towards the kitchen after putting on PPE to protect herself and to avoid contaminating the evidence, while waiting for her outside the kitchen, Ronnie asked.
"Did you figure out something? Are you sure you don't want to keep listening?"
Camila looked back at Ronnie, kept the kitchen door open for a brief moment to reply.
"I think I may have an idea, a crazy idea, but it might be true. You go back to listening in on the questioning of the staff members, with special attention to Emma. I'll be looking for something."
Camila let go of the kitchen door, letting it close before she walked towards the kitchen sink.