That bratty King Joffrey is dead (spoiler!), and the latest episode of HBO's "Game of Thrones" laid out the details behind who poisoned him, how and why. But at least one question is still under debate: Which real-life poison is most like the deadly crystalline concoction known in George R.R. Martin's saga as the Strangler?
For Deborah Blum, author of "The Poisoner's Handbook," cyanide is the prime suspect: "Cyanide would make you feel like you're suffocating and choking," Blum told NBC News. A real-life parallel can be found in 2012's courtroom suicide of a former Wall Street trader convicted of arson.
Another parallel to Joffrey's death by choking: Cyanide does not leave behind a pretty corpse. The poison is so destructive to the insides that blood froths through the victim's mouth.
There's no need for Martin to make his fictional poison conform strictly to reality, of course, and that means there's room for alternate theories.
Doane College chemist Raychelle Burks focuses on plant-based alkaloids, because the Strangler is said to come from plant leaves. Her prime suspect is strychnine, which causes spasms and breathing difficulties.
Burks said pop-culture poisonings can be "a good way to get people talking and thinking about science, and about chemistry in particular." Amen to that.
Poisoning was a mysterious path to murder in medieval times, as Blum explains in her book. So it's no wonder that the maesters of "Game of Thrones" would be mystified by Joffrey's death.
"We didn't learn how to detect poisons until the 19th century," Blum said. "The first test for any poison in a dead body didn't happen until 1838."
If you're looking for a real-life analog to Martin's poisoners of Lys, look no further than the Borgia family of 16th-century Italy. Lucrezia Borgia is said to be one of the inspirations for Martin's tale, along with historical figures from England's Wars of the Roses.
"What the Borgias were famous for is, they took the standard poisons and mixed them up and amplified them to make them worse," Blum said. "They were masters of saying, 'Yeah, this poison is bad, but it's not bad enough.' ... The rumor is that those recipes are still somewhere in some vault in the Vatican."
Update for 9 p.m. ET April 29: And there's yet another prime suspect: nicotine, as explained by Justin Brower on the Nature's Poisons blog. "At least that's my story and I'm sticking to it," Brower writes. Thanks to Raychelle Burks for the pointer.