A man befriends a fellow criminal as the two of them begin serving their sentence on a dreadful prison island, which inspires the man to plot his escape.

Henri “Papillon” Charrière, a safecracker from the Parisian underworld, is wrongfully convicted and sentenced to life imprisonment in the penal colony of French Guiana, where he forges a strong friendship with Louis Dega, a counterfeiter who needs his protection.