"Papillon" follows Henri Charrière through a series of harrowing escape attempts and brutal punishments. His first escape with Dega and another inmate, Maturette, ends in failure after they are betrayed. Papillon is sentenced to two years in solitary confinement. During this time, he nearly starves and loses his mind but refuses to betray Dega, who had arranged for coconuts to be smuggled to him. Upon release, he immediately plots another escape. This attempt is initially successful; he lives for a time with a native tribe in Honduras and has a relationship with a young woman, Zoraima. However, he is eventually betrayed by a nun at a convent where he seeks refuge and is recaptured.
His punishment for the second escape is five years in solitary. He emerges a much older, gray-haired man, physically diminished but with his will intact. He is then transferred to the inescapable Devil's Island, where he reunites with an aged and resigned Dega. Dega has adapted to life on the island, tending a small garden and having given up all hope of freedom. Papillon, however, studies the ocean currents and devises a final, seemingly suicidal escape plan: to jump from a high cliff into the sea on a makeshift raft of coconuts. Dega, too broken and afraid, refuses to join him. After a heartfelt goodbye, Papillon makes his leap of faith. The powerful waves carry him out to sea. A concluding narration reveals that Henri Charrière made it to freedom and lived the rest of his life as a free man, while the penal system itself was eventually closed. The hidden meaning that becomes clear is that Papillon's relentless obsession was not madness, but the only sane response to an insane system, and his final, desperate act was the ultimate affirmation of life.