Dr. Cyanide is a main antagonist in the first season of PetersCorporal's fangame.
Dr. Cyanide was a serial poisoner who would use cyanide on the victims but after a few poisonings, the dose was never enough to kill the person, plant, or animal. Somehow, Dr. Cyanide always knew what the player's team was doing and used that knowledge to terrorise them and even managed to cause on Evan Day a grudge for Daniel Mossle.
The first time that the team had news of Dr. Cyanide's poisonings it was because of Peter Galley's petunia. He told the team about it and after taking a sample from the flowerpot, Sabrina Stone saw that the petunia had been poisoned with cyanide and supposed that it was already most probably dead. It was very weird to see that someone would poison a flower but the team didn't worry too much about it until later.
Two months later, Wendy Ohdie asked the team for help because a fern she had planted in a park suddenly started getting worse. The team was not interested in her fern at all but decided to help her. Sabrina saw that this plant had been poisoned with cyanide as well. This time, Evan Day started considering the issue a bit more important. It would be bad if there was a serial poisoner attacking plants since they might cause bigger trouble.
Other two months later, the police were now investigating the murder of Alberto Gandil, a mayoral candidate, in the City Hall. In front of the City Hall, Lucy Loas (another mayoral candidate who killed Alberto) had a catering house. During the investigation, someone had broken into the catering house. When they returned there with Lucy, she said that a bottle of cyanide was missing. She had one because she was going to use it to kill Alberto but later she decided roach poison would be better.
Gino Reina and the player noticed the connection between the missing cyanide from the catering house and the other two cyanide poisonings, thinking that it should be the same person who had done both. Gino nicknamed them "Dr. Cyanide".
Dr. Cyanide called the team and after reading a newspaper article about the poisonings and the catering house break-in, said to the team that Dr. Cyanide was the one calling. Evan Day was a bit confused because the serial poisoner had actually called to help them with the case they were investigating. In a later call, they said that they motive for the poisonings was that they "wanted to know how he died".
After being arrested, Linda Farren said that she knew who Dr. Cyanide was and why they were doing that. Both her and Dr. Cyanide (in another phone call) revealed that the number 27111918 was somehow related to them. In fact it was a date, being it the 27th of November in 1918.
The team found out that a little parrot called John, owned by Ximena Rodeland, had been poisoned by Dr. Cyanide. This time as well, the dose was under the lethal amount required to cause death, so the parrot survived.
Charlie Framel said to the team that his rabbit, Jimmy, had been poisoned by Dr. Cyanide months ago but hadn't died. The same day when Charlie told the player about this, Dr. Cyanide poisoned one of Sabrina Stone's strawberry parfaits.
4 and a half months after Harry's suicide, Linda Farren said in a phone call that Harry Clover was not Dr. Cyanide. Later on, they called the team and said that they were in trouble since they couldn't fulfill their goal of knowing "how he died".
The team found out that Dr. Cyanide's first victims were some plants from the local greenhouse and were also helping Miranda Flores (Harry's cousin) with her investigation on the serial poisoner, since Harry had told her about it on a videocall.
Dr. Cyanide indirectly but intentionally revealed that they were part of the Black Eagle Society. The serial poisoner used Evan Day to confirm some information about Lindsey Vain being under preventive imprisonment. Evan unfortunately spilled the beans and Bryan Stefode kidnapped Lindsey.
The team discovered that Dr. Cyanide managed to bring Green Year Parade back with Mirtha Gray's help. It was in fact so that the dead flowers could be used as part of the cyanide experiments. Besides, they found some secret microphones in their police station that Dr. Cyanide had left there a year and a half ago to listen to what the team said everytime they spoke. Evan, led to a false conclussion because of Daniel Mossle's family secrets, arrested him for being Dr. Cyanide.
The team found out why Dr. Cyanide had made Green Year Parade return thanks to Paul Waters' (who committed suicide that day) documents.
The police arrested Barbara Thacks for the murder of Linda Farren. She said she had betrayed her after she helped her escape from the police but in fact they later saw that it was because Barbara was Dr. Cyanide and she had finally killed her target. Barbara confessed when she was already in jail and said that her motive was to find out how an ancestor of hers had died around 100 years before. Linda was her target because the Farrens had killed her ancestor and they were involved in some kind of family feud.
In this case, Barbara became one of the suspects. The team found out that she had recorded several voice notes explaining to Bryan Stefode what the team was investigating about the Black Eagle Society. However, Bryan was kidnapped at Paul Waters' hands in that moment so Paul would listen to her voice notes and send the mobile phone back to her. This meant that when Paul died, he knew that the police would eventually find out he was the true leader of the society.
Frida Larry revealed to the team that the family feud involving Dr. Cyanide and Linda Farren's family had originated in Blue Coasts. Just in case there was more to the story than they knew (which in fact was true), the player was transfered to the Blue Coasts Police Department.
The first hint that the team got about Dr. Cyanide was that they had something in common with Doodley, who was known for being a thief. One of the other very few professional thieves in Townville was Barbara.
Ximena Rodeland thought that Dr. Cyanide, who was responsible for her parrot's poisoning, was El Pantera, who lived in the building next door. Barbara also lived in that building.
Dr. Cyanide poisoned Sabrina Stone from inside the team's headquarters. If it was not someone from the police, it had to be someone very skilled to break into the building, such as Barbara, who had experience from her robberies.
Why Harry Clover said he was Dr. Cyanide: they had dated and Barbara helped him not to out himself.
It was shown that Harry didn't want to come out of the closet, since nobody knew about his relationship with Orlando Edra, and he had even said that they were "roommates" while talking to the player.
It was also shown that Barbara had "a thing" for gay and feminine guys, as shown when she tried to flirt with Octavius Keys (even though she invented an excuse for that) and also dated Orlando Edra.
Barbara was truly shocked when Gino Reina told her that Orlando had also dated Harry, since she was the one dating Orlando at the moment. Her surprise was not because of Orlando not being straight, since later he mentioned that he had already told Barbara he also liked guys. The motive of her shock was hence something else, actually the fact that she had also dated Harry and had told him that she was Dr. Cyanide.
Octavius Keys said he'd heard a mysterious "day" sound when Dr. Cyanide cut the call. That was in fact Jessica Newman's "daily discounts" phrase, which was used purposefully as a running gag in The Botanical Killer as she even said it when she was in jail. Barbara had also said that she had friends in the botanical garden who knew a lot about makeup. Moreover Jessica, London Brighton, and Miranda Flores had told them that Dr. Cyanide had poisoned plants in the botanical garden's greenhouse.
Barbara called Evan Day's mobile to ask them to save Tiffany Granell's life instead of calling the headquarters. She did not say how she had obtained his phone number but it had been shown that Dr. Cyanide had called his mobile more than once.
Jessica Newman told the team that Dr. Cyanide had said, a few days before Laurean Ohdie's murder, that they'd just arrived in Townville by plane. The only big reference to a plane flight before Jewels Of Death was another case, End Of The Flight. Barbara had been a suspect in that case, and the rest of the case's suspects were practically minor characters who did not appear in any other case. This also showed that Dr. Cyanide was not someone from the team as Evan had suspected after Sabrina's poisoning, because they had been in the city for years and years before Laurean's death.