The series follows the adventures of three orphaned siblings. Lemony Snicket documents their lives and explains to the readers that very few positive things happen to the children.

The series begins when the orphans are alone at a beach, where they receive news that their parents have been killed in a fire that also destroyed the family mansion. In , they are sent to live with a distant relative named after briefly living with , a banker in charge of the orphans' affairs. The siblings discover that Count Olaf intends to get his hands on the enormous Baudelaire fortune, which Violet is to inherit when she reaches the age of eighteen. In the first book, Olaf attempts to marry Violet to steal the Baudelaire fortune, doing so by pretending that the marriage is the storyline for his latest play. The plan falls through when Violet uses her non-dominant hand to sign the marriage document, thus causing the marriage to be invalidated. After the crowd realizes, Olaf manages to escape with his henchmen.

In the following six books, Olaf disguises himself, finds the children, and, with help from his , tries to steal their fortune, committing arson, murder, and other crimes. In books eight through twelve, the orphans adopt disguises while on the run from the police after Count Olaf frames them for a murder he has committed. The Baudelaires routinely try to get help from Mr. Poe, but he, like many of the adults in the series, is oblivious to the dangerous reality of the children's situation.

As the books continue, another running plot is revealed concerning a mysterious secret organization known as the Volunteer Fire Department (V.F.D.). From onwards, the connections between the Baudelaires, the V.F.D., and their parents' deaths are slowly revealed, leading the siblings to question their previous lives and family history. The siblings become increasingly involved with the organization until they are forced to flee with Count Olaf to an island where Olaf accidentally causes the deaths of himself and possibly the idyllic colonists of the island, whose fates are left unknown. Having finally found a safe place to live, the children spend the next year raising the baby of one of their parents' friends from V.F.D. who died giving birth to the child. After a year, the siblings decide to try to return to the mainland to continue their lives.

Source: Wikipedia