The Dust of Death (Unabridged‪)‬

Doc Savage finds himself caught in the middle of two embattled South American republics that have found a new and deadly foe in the form of an evil hooded figure known as the The Inca in Gray. When The Inca deploys a deadly "Dust of Death" to slaughter citizens on both sides of the fighting, Doc Savage and his team rush into the battle to try to save the day and avoid the firing line.