The show focuses on Mitsuko Aoyama (1874-1941), who was the first Japanese woman to marry a westerner.
An aristocratic child forms a contract with a demon to fulfill his wishes and help him take revenge on his parent's murderer. Meanwhile, a string of murders terrorize London. These murders however, do not appear to be of the mortal world.
Third stage play in the Fullmetal Alchemist Stage series, focusing on the Briggs arc.