[1] The book begins with the Baudelaire orphans and Count Olaf on a boat heading away from the burning Hotel Denouement.

The Islanders, led by a man called Ishmael (who, multiple times, says that "he won't force them" to do what he wants), capture him and shun the Baudelaires for possessing forbidden items.

Agreeing, the Baudelaires go to the arboretum to collect weapons, where they discover a hidden room with a book that chronicles the history of the island.

Ishmael harpoons Olaf in the stomach, inadvertently shattering the helmet containing the Medusoid Mycelium, a deadly fungus, infecting the island's entire population.

While reading through the book left by their parents to find where the horseradish is hidden, the three continue to be affected by the fungus and, after some deliberation, accept their deaths.

Ishmael promises that he will save the islanders by sailing to a horseradish factory, but refuses to give them the apples, despite having already consumed one himself.