Foreshadowing
The Bad Beginning contains the first references to Beatrice and to the V.F.D. eye insignia, which later become major plot devices. The book also contains the first mention of the High Court, which is one of the primary instruments through which Olaf tracks the Baudelaire orphans' guardianships.
On page 28, Snicket states, "Your initial opinion on just about anything may change over time," referring to the possibility that Count Olaf is not a bad as he may seem. On page 62 of The End, Ishmael utters exactly the same words to the Baudelaires, referring to their discomfort with the customs of the island; these customs eventually bring about the islanders' apparent deaths, but in the same book the children do ultimately feel some sympathy for Olaf. On the drive to Olaf's house, the children and Arthur Poe pass the Royal Gardens, described as "an enormous pile of dirt". In The Grim Grotto, the Baudelaires read that Jacques Snicket formerly investigated the arsonous destruction of these Gardens.
Near the end of The Bad Beginning, Count Olaf traps Sunny inside of a birdcage. In The End, Olaf is trapped by the colonists of the island on the coastal shelf inside a large birdcage when his final scheme is foiled. Similarly, just as Mr. Poe comes to retrieve the children at Briny Beach after their parent's arsonous death in the beginning of The Bad Beginning, Poe comes to retrieve them from Briny Beach a second time in The Grim Grotto just before they burn down the Hotel Denouement, a fire which results in the death of almost every secondary character in the series.
In addition, Snicket makes reference to an island which "has a law that forbids anyone from removing its fruit". In The End, the Baudelaires shipwreck on an island where removing the apples from its single fruit tree is a symbolic gesture of self-exile. Furthermore, Justice Strauss tells the Baudelaires she is involved in a case concerning "a poisonous plant and illegal use of someone's credit card". This may refer to the poisonous mushroom Medusoid Mycelium featured in many of the later books; while strictly a fungus, popular belief holds that mushrooms are plants.
The final illustration in the book shows a snake curled around a lamppost, an allusion to the next book, The Reptile Room.
Read more about this topic: The Bad Beginning