The fictional author describes meeting Pi in Pondicherry after years of creative failure in India, and promises a story that will 'make you believe in God.'

Pi explains how he acquired his name — from the Piscine Molitor pool in Paris — and how, at a new school, he preemptively renamed himself 'Pi' to escape bullying.

Pi's father runs the Pondicherry Zoo. Pi grows up with encyclopedic knowledge of animals. His father demonstrates, terrifyingly, that wild animals are never truly domesticated — by feeding a goat to a tiger in front of his sons.

Pi discovers Hinduism, Christianity, and Islam sequentially and refuses to choose between them. He meets two Mr. Kumars — his Muslim baker and his rationalist biology teacher — who represent the novel's two poles of belief.

The Patel family boards the Japanese cargo ship Tsimtsum to emigrate to Canada with zoo animals. The ship sinks in a Pacific storm. Pi survives on a lifeboat with a zebra, hyena, orangutan, and a Bengal tiger.

The hyena kills the zebra and then Orange Juice. Richard Parker kills the hyena. Pi is alone with the tiger. He claims territory, establishes dominance through a sea anchor 'whistle' and seasickness training, and begins to survive.

Pi develops survival routines — fishing, harvesting rainwater, managing Richard Parker. He witnesses storms, bioluminescent nights, a whale breach, flying fish raining onto the boat. He begins to lose his grip on conventional reality.

The lifeboat arrives at a mysterious floating island of algae populated by meerkats. Pi and Richard Parker recover. But Pi discovers the island is carnivorous — it digests living things at night. He leaves.

The lifeboat reaches the Mexican coast. Richard Parker walks into the jungle without looking back. Pi is found and hospitalized. He tells the Japanese investigators the animal story; they disbelieve it; he tells a human story using the same structure. He asks which they prefer.