The action is relentless enough to distract you from the fact that this is basically a side mission, not the story that matters. Julia's conviction to burn everything down for her people has weight even when the plot doesn't, and Ed and Al feel like they're genuinely out of their depth for once. What sells it is that the movie knows it's not canon and moves too fast to care, it's a perfect two-hour ride for people who just want to watch the brothers fight something they can't alchemy their way out of.
Edward and Alphonse stumble into a powder keg when they pursue a mysterious runaway alchemist into a distant valley. There they discover the Milos, a proud people living in slums after the militaristic nation of Creta seized their land. The brothers soon find themselves caught in the middle of a growing rebellion determined to reclaim that homeland. Julia, a young alchemist and Alphonse's new friend, longs to see her people restored. She is willing to go as far as using the Philosopher's Stone, the very object the Elrics have been searching for, but their past experiences with it leave them unwilling to help. As they uncover Creta's intentions and its murky history, they are pulled into the fight between the Milos and the Cretan military. The film mixes action, adventure and drama with moments of comedy.
Streaming Fullmetal Alchemist: The Sacred Star of Milos legally, as of the last catalog refresh. Availability changes by region.
Bilibili