The strangler is a rare poison that looks like dark purple crystals, and makes the victim unable to breathe. The process of making the poison is known to the alchemists of Lys, the Faceless Men of Braavos, and the maesters of the Citadel. The maesters do not discuss the subject beyond the confines of their order. The Asshai'i have one name for the plant from which the poison is made, and the alchemists of Lys have another name for the crystals, but the maesters call the poison the strangler.
The process to make the strangler is slow and difficult, the necessaries costly and hard to acquire. The poison is made from plants that are only found on islands in the Jade Sea. The leaves of the plant are picked and aged, then soaked in a wash of limes, sugar water, and rare spices from the Summer Islands. The leaves are then discarded, but the liquid is kept and thickened with ash and allowed to crystallize. The crystals are dark purple, no larger than seeds, and shine like jewels.
Dissolved in wine, the strangler makes the muscles of the victim's throat clench tighter than a fist, shutting off the windpipe. It is said that the victim's face turns as purple as the poison crystals. The effects can be mistaken for choking on a small piece of food.
A Clash of Kings
Maester Cressen attempts to assassinate Melisandre using the strangler, but she survives after drinking almost the whole poisoned cup of wine. When Cressen drinks the remaining half a swallow from the same cup, he dies.
The fool Ser Dontos Hollard provides Sansa Stark with a silver hair net, decorated with what he claims to be black amethysts from Asshai. He claims the net is magic that will give Sansa justice, vengeance for King Joffrey Baratheon's execution of her father Eddard Stark, and take her home to Winterfell.
A Storm of Swords
Sansa Stark wears the silver hair net to the royal wedding of King Joffrey Baratheon and Margaery Tyrell, per Dontos Hollard's orders. During the wedding, Lady Olenna Redwyne secretly takes one of the crystals from the hair net and uses it to poison the wine in King Joffrey's goblet. Joffrey appears to choke on a piece of his wedding pie, and dies, unable to breathe. The wine, originally red, has turned purple.
Sansa, fleeing the Red Keep in the chaos of the assassination, discovers that one of the amethysts in her hair net is missing, and later learns that Dontos was given the hair net by Lord Petyr Baelish. Petyr tells Sansa that he and Lady Olenna conspired to murder Joffrey and frame Tyrion Lannister.
Such a small thing to hold the power of life and death.
They said a victim's face turned as purple as the little crystal seed from which his death was grown, but so too did a man choking on a morsel of food.
—the ghost of High Heart
- A Clash of Kings, Prologue.
- A Storm of Swords, Chapter 66, Tyrion IX.
- A Clash of Kings, Chapter 65, Sansa VIII.
- A Storm of Swords, Chapter 16, Sansa II.
- A Storm of Swords, Chapter 60, Tyrion VIII.
- A Storm of Swords, Chapter 61, Sansa V.
- A Storm of Swords, Chapter 68, Sansa VI.
- A Storm of Swords, Chapter 43, Arya VIII.