Gunpowder is referred to as Greek Fire, and Djaq complains about name, claiming it as a Muslim invention. However, this is wrong on three levels. First, it would be another fifty years or so before gunpowder was known in Europe. Second, Greek Fire and gunpowder are wholly separate: gunpowder is a charcoal, sulphur and saltpetre-based explosive powder; Greek Fire is the petroleum-based liquid fuel for a type of medieval flamethrower. Finally, Greek Fire was indeed an invention of the Byzantine Greeks; gunpowder was a Chinese invention exported to the Islamic world.