"Indeed, it would be impossible. But it seems that wildfire only gets more volatile and potent as it ages, and the royal patronage in question was Aerys Targaryen. I managed to get ahold of a former acolyte alchemist that left the guild after Robert's Rebellion. If the wildfire had twenty years to age, only fifteen hundred barrels would have been more than enough to destroy the city. And Aerys had ordered twice the amount made, before the Sack of King's Landing," Olenna explained with a dangerous glint in her eyes. "We truly underestimated how deep his madness ran. Jaime Lannister running down the Pyromancers in the Red Keep and slaying his king makes far much more sense now."