Dave, a fehru-alchemist, returns to Rhi-Daton, the city he previously fled, following a series of unsettling events. Concurrently, a mysterious woman with unique abilities allies herself with House Dawn to secure a specific weapon before it falls into undesirable hands. The situation escalates when Rhi-Daton's gates are unexpectedly sealed, trapping everyone inside. Dave encounters Leto, another alchemist, within the confined city. Together, they must work to uncover hidden truths from the past.