Friday is Michel Tournier's 1960s retelling of the Robinson Crusoe story. Crucially, Tournier changes the point of view from a first-person account to a third-person omniscient perspective interspersed with Crusoe's first-person journal entries. This significantly changes the tone of the original. While Defoe's narrative is imbued with the sincerity and unifying force of Crusoe's voice, Tournier's perspective allows him to depict Crusoe more wryly and negatively. Further, the third-person perspective enables Tournier to penetrate and reveal Friday's thoughts, something completely absent from the original book.

As in the original, Crusoe ends up the sole survivor of a shipwreck, a castaway on a deserted island. After a period of near madness, Crusoe, as in the original, scavenges what he can from the submerged ship and, to keep his sanity, engages in a project of farming and domesticating his island. He builds a home, The Residence, designs a timekeeping device, writes laws, plants crops, keeps great stores of grain, battles rats, and creates a rice paddy while following a rigid schedule. Unlike the original Crusoe, this Robinson reincarnation is a Quaker, so he holds Quaker meetings in which he reads a Bible he salvaged from the ship.

Tournier shows much of Crusoe's activity to be ridiculous, but he also exhibits sympathy for Crusoe's need to impose order to stay sane. However, as his journal entries reveal, Crusoe realizes he has not achieved an adequate life or relationship with the island, which he has named Speranza. He believes there is a metaphoric second island behind the one he has done his best to dominate and control. He believes he is in a process of change.

He begins to have sex with the island, using the moss-filled opening in a fallen tree, and is both surprised and pleased when mandrake-like flowering plants start growing near this place, the offspring of his "union" with Speranza.

As in the original novel, Crusoe saves the life of Friday. In this incarnation Friday is a part Indian, part black teenager who Crusoe initially considers his slave and inferior. He makes Friday work hard and conform to his European norms and hits or beats him when Friday does not meet his expectations. Although Friday complies readily with his demands, Crusoe still often feels frustrated with him, sensing that Friday does not share his mindset.

All of this changes when Friday accidentally floods the rice paddy and accidentally ignites Crusoe's gunpowder stored in the cave near The Residence. When all of his "stuff" is blown up, Crusoe undergoes an important and radical change. No longer is domination important to him. Because of this, he begins to see Friday as an equal and as someone he can learn from as well as teach. He learns to love Friday and see his body as beautiful rather than "other." Crusoe finds his authentic self and the metaphoric "second island" behind the one he tried to control. Now he lives in harmony with both Speranza and Friday.

When a European ship arrives on the island after 28 years, Crusoe is disturbed by the greed and anxious desire he sees in the crew. He decides to stay behind but is devastated when he realizes that Friday has left with the ship. He decides it is time to die and heads for a crevice in his cave where he once before did battle with life and death. En route, he meets up with a young boy, Jaan Neljapäev, who was beaten and abused on the ship. Jaan tells him he escaped to be with Crusoe because he saw that Crusoe had kind eyes. Now that he has a companion, Crusoe is renewed, and the story ends.