Baccano! 1931 The Grand Punk Railroad

A group of alchemists in 1711 sought eternal life by summoning a demon on a boat. The demon offered them an elixir, the means to reproduce it, and the method to end their immortality. Soon after, the alchemists began vanishing, apparently consumed by one of their own. To avoid further danger, they dispersed globally. In 1931, during the Prohibition era in America, these immortals reunite, sparking a chaotic event.