After the rebel victory of Robert Baratheon at the Battle of the Bells Aerys was fearful that Robert might actually win the war and enlisted the aid of several members of the Alchemists' Guild in a plot to destroy the city of King's Landing should the rebel forces prove victorious. Jaime Lannister was present when all of this was being planned, while the rest of the Kingsguard was absent and went with Prince Rhaegar.
Thousands of jars of Wildfire were gathered and placed in key positions under Kings landing. hundreds were placed under the Dragonpit and the Great Sept of Baelor, under every one of the city's gates and even under the Red Keep itself. The pyromancers did all their work in secret and did not even trust their own apprentices with the knowledge .
The rest of the royal family were unaware of this; apparently the queen's eyes had long been shut to her husband's insanities, and Rhaegar was busy marshalling an army, but the Hand of the King, Lord Qarlton Chelsted grew suspicious of the constant comings and goings of the pyromancers from the Red Keep. When Chelsted discovered the plot, he confronted Aerys, and when reasoning, threatening, jesting and even begging on his part failed to dissuade Aerys from this course of action, Chelsted resigned his handship, flinging his chain of office at Aerys' feet. Aerys had him burned alive for this and made Rossart his new Hand of the King. 
During the Sack of King's Landing, Aerys commanded Rossart to ignite the wildfire to destroy the city. Jaime Lannister however intercepted and slew Rossart he then slew Aerys, plunging his sword into the Mad King's back, to prevent his message from reaching another pyromancer. Jaime a few days later hunted and killed Garigus and Belis the other pyromancers involved in the plot .
- King Aerys II
- Lord Rossart of the Alchemists' Guild
- Wisdom Garigus of the Alchemists' Guild
- Wisdom Belis of the Alchemists' Guild