It's a crossover of characters from two universes: "Murder Drones" and "Avatar the last airbender". Drones have entered the avatar world where there are 4 elemental nations - water, earth, fire and air. All the nations lived in peace and harmony until the Fire Nation started a war. Only the avatar, the master of all four elements, can stop the invaders. But for now, Aang is just learning his elements, and his friends Katara, Toph, Zuko, Sokka and Suki are helping him. 