Life of Pi tells the fantastical story of Pi Patel, a sixteen-year-old South Indian boy who survives at sea with a tiger for 227 days. Pi, born Piscine Molitor Patel, grows up in the South Indian city of Pondicherry, where his father runs the zoo. A precocious and intelligent boy, by the age of fifteen Pi—Hindu from an early age—has also adopted Christianity and Islam, and considers himself a pious devotee to all three religions.
Thanks to government upheaval that has long been distressing Pi’s father, the Patels decide to close the Pondicherry Zoo and move to Canada when Pi is sixteen. Pi, his mother, father, and brother Ravi all board the Tsimtsum along with the zoo’s animal inhabitants (who are on their way to be sold around the world).
An unexplained event causes the Tsimtsum to sink, and Pi is the only human to make it onto the lifeboat and survive. Along with Pi, the lifeboat contains a hyena, a zebra, Orange Juice the orangutan, and Richard Parker the tiger. The hyena kills and devours both the zebra and Orange Juice, before Richard Parker kills the hyena. Pi is left alone on a lifeboat with an adult male tiger.
There is no land in sight and the ocean is shark-infested, so Pi builds a raft which he attaches to the lifeboat, to keep himself at a safer distance from Richard Parker. Eventually, however, life on the raft proves too exhausting, and Pi realizes that if Richard Parker gets hungry enough, he will swim to it and kill Pi. So Pi decides that he must tame Richard Parker. Using a whistle, seasickness, and a turtle-shell shield, Pi manages to assert his authority over Richard Parker and delineate his own territory on the lifeboat, where he is comparatively safe from the tiger.
While at sea, Pi and Richard Parker face many challenges, traumas, tragedies, and miraculous occurrences. They never have sufficient food and fresh water, and the constant exposure is highly painful. A severe storm, which they miraculously survive, destroys the raft. Pi manages to capture and kill a bird. They are almost crushed by an oil tanker, which then passes by without seeing them.
During an especially severe period of starvation, Pi and Richard Parker both go blind. While blind, Pi hears a voice, and realizes that they have drawn near another lifeboat that contains a similarly starving and blind Frenchman. Pi and this man converse for a while, and bring their boats together. The Frenchman climbs onto Pi’s boat, and immediately attacks him, planning to kill and eat him. He doesn’t realize that there is a tiger on the boat, however, and accidentally steps into Richard Parker’s territory. The tiger immediately attacks and kills him. Pi, saved at the cost of his attacker’s life, describes this as the beginning of his true moral suffering.
Pi and Richard Parker come upon a weird island that is made of algae with trees protruding from it, teeming with meerkats but no other life. Pi and Richard Parker stay on the island for weeks, eating the algae and the meerkats, growing stronger, and bathing in and drinking from the fresh water ponds. They never stay on the island at night, however, Pi because he feels safer from the tiger in his delineated territory, and Richard Parker for a reason unknown to Pi. Pi eventually starts to sleep on the island, and while doing so realizes that the island is carnivorous—it emits acid at night that dissolves anything on its surface. Greatly disturbed by this, Pi takes Richard Parker, and they leave the island.
Pi and Richard Parker eventually land on the Mexican beach. Richard Parker immediately runs off into the jungle without acknowledging Pi, which Pi finds deeply hurtful. Pi is found, fed, bathed, and taken to a hospital. There, two Japanese men come to question Pi about what caused the Tsimtsum to sink. He tells his story, which they do not believe, so he offers them a more plausible version, with the animal characters replaced by other humans, which casts doubt on the original story.
Throughout the novel, the story is interrupted by the author’s notes on Pi as he is now, telling this story to the author. After recovering in Mexico he went to Canada, where he spent a year finishing high school and then studied Religion and Zoology at the University of Toronto. At some point, he got married, and he now has two children. He still thinks of Richard Parker, and is still hurt by his final desertion.