The Volunteer Fire Department (V.F.D.) is a secret organization dedicated to the promotion of literacy, classical learning, and crime prevention within the book series A Series of Unfortunate Events by Lemony Snicket. V.F.D. is an abbreviation for various terms related to the organization, which helps to increase the reader's confusion of what the initials actually stand for. The Baudelaires excepted, the meanings are perfectly clear to the organization's members.
V.F.D. was first mentioned in The Austere Academy when Duncan and Isadora Quagmire were researching Count Olaf. At the climax of the book, they reveal that they have discovered an important secret, but are kidnapped by Olaf before they can tell the Baudelaires. There are mentions of V.F.D. in every book in the series following The Austere Academy. The theme becomes increasingly prominent in subsequent volumes as the Baudelaire orphans investigate the initials' true meaning, and it appears to figure centrally in their parents' deaths and the schemes of their enemy, Count Olaf. It eventually transpires that it is the name of a secret organization. The Slippery Slope suggests that V.F.D. stands for 'Volunteer Fire Department', among other things; in The End Lemony Snicket's narration confirms that 'Volunteer Fire Department' is the correct meaning of the initials. In The Grim Grotto, it is revealed that while this was the origin of the organization, its members had many other interests.
While the name "Volunteer Fire Department" connotes a group that actively puts out fires (metaphorically as well as literally, according to Kit Snicket), it can be read to mean a group that actively starts fires (something of an allusion to the "firemen" in Ray Bradbury's Fahrenheit 451), which indeed happens when the group is split because of a schism. One group of Schismatics fights fires and the other half are arsonists. When the Schism occurred and exactly why it occurred is unknown, except that it was in the childhood of Kit Snicket and Dewey Denouement and that it appears that a line has been drawn between those who stop fires and those who start them. The members of the former are called "volunteers" and the members of the latter are called "villains". The "volunteers" often appear to be desperate, in that their situation seems to be one of dire straits. It is openly stated that the "villains" are growing more powerful and the "volunteers" weaker; however, the epilogue of the thirteenth and final book suggests that after the events therein, the "volunteer" half of the organization seems to have survived or recovered, while the "villain" half has returned to its former power.
The protagonists of the series (Violet, Klaus and Sunny Baudelaire) discover that their parents were members of this secret organization, as were many of the guardians they were placed with after their parents' death, along with various other people they encounter throughout the books.