Atroquinine is a synthetic substance that is extremely poisonous to humans. It is a very potent poison (lethal at 2 µg) that paralyzes the nervous system. It takes at least 15 minutes after ingestion for adverse effects to show. Symptoms include trembling of the limbs, arching of the back, and burning of the throat.
The name of the poison features in the 2025 Gavinners' platinum hit song "Atroquinine, My Love".
- Main article: Turnabout Succession
When Kristoph Gavin visited the home of Drew Misham to request a forgery, he left a commemorative stamp of Troupe Gramarye and a bottle of nail polish, both of which he had laced with atroquinine, to prevent Misham from talking about him. He told Drew's daughter Vera that the nail polish was a magic charm that would protect her from danger, and he instructed Drew by letter to send a reply confirming receipt of his payment for the forgery. However, Vera grew fond of the stamp and left it in a frame. Seven years later, Drew sent a letter to Gavin, telling him to remove the "magic charm" that Vera would talk about but not identify; lacking a stamp, he used the poisoned one, which killed him.
Vera became the prime suspect for his death, and was called to the witness stand during the course of the subsequent trial. However, she quickly became nervous and bit her nails, which had the poisoned nail polish on them, and fell into a coma. Luckily, she survived the incident, making her the only known individual to have survived a near-lethal dosage of atroquinine poisoning to date, and was found not guilty for her father's murder.
- Atroquinine's name may be based on the real-life chemical quinine, which is used to treat malaria. The prefix "atro-" is based on a Latin word meaning "dark", so "atroquinine" could literally mean "dark quinine".
- Alternatively, the name may be a portmanteau of "atropine" (a potentially deadly tropane alkaloid extracted from, amongst others, deadly nightshade and used as a drug with a wide variety of effects) and "quinine". Since atropine can be potentially deadly, it is named after Atropos, one of the three Fates in Greek mythology who would choose how a person was to die.