Final answer:
Pi discovers that the seemingly safe island is actually carnivorous and dangerous, which prompts him to leave and return to the ocean.
Step-by-step explanation:
The bizarre discovery that Pi makes about the true nature of the island in Yann Martel’s novel Life of Pi is that the island, which at first appears to be a sanctuary, is carnivorous and dangerous. During the day, the island seems like a haven with fresh water and food, but at night, it reveals its true, menacing nature by turning acidic and capable of consuming flesh. This revelation forces Pi to reassess his situation and make the difficult decision to leave the island and face the uncertainties of the ocean once again.