The two brothers Alec, separated in two worlds, use their own methods to try to reunite. The elder brother Edward came to the real world through the "door". In Munich, Germany in 1923, a world war was about to come. Edward, who could not use alchemy in this world, studied rocket technology with Alphonse, a young man who looked like his brother, hoping to return to the original world with the help of rockets. In the other alchemy world, the younger brother Alphonse practiced alchemy, dressed like Edward in the past, and worked with the national alchemists to find a way to find his brother. In secret, a mysterious organization in Munich began a ritual to find the ideal country "Shambhala", and the "door" connecting the alchemy world and the real world was opened. The fate of the two brothers is intertwined with the crises of the two worlds, and the Eric brothers have to face unprecedented challenges.