From Baka-Tsuki:
Baccano, which the author Narita translates as "stupid commotion," is Italian for "ruckus" and, when spelled with Japanese script, contains "baka" which means "stupid." Each of the stories in the series involves several unrelated plots intersecting and crossing each other as events spiral farther and farther out of control. Immortal alchemists, a mafia-operated speakeasy, secret societies and many other elements of pulp fiction mashed together for a world straight out of classic movies.
The ruckus all started 300 years ago on a boat where the alchemists summoned a "demon" in order to obtain the method of immortality. The demon gave the alchemist the liquor of immortality. the only way to die is to to be devoured by another immortal, which passes down all knowledge the consumed person possesses—and only one person was given the method to produce more liquor.
The following night, one of the alchemists started to devour his companions. To escape this threat, the alchemists scattered all over the world.
In the America of Prohibition and the temperance movement, centering around the liquor of immortality, the "stupid commotion" starts within the narrow confines of a non-stop train speeding through the night...

Note: Winner of the Gold Prize at the 9th Dengeki Novel Awards.