At the opening of Foe, Susan Barton washes up on the shore of a small rocky island, somewhere in the South Seas, sometime in the early eighteenth century. She is found by Friday, a black man with bare feet. Friday brings her to Cruso, a weather-beaten white man with a peaked straw hat. Susan remarks on the race of both men. Because he’s white, she considers Cruso to be Friday’s master. Friday doesn’t speak. Susan tells Cruso her story: she was born of an English mother and a French father. She has a daughter was abducted by an Englishman and taken to the New World. Susan followed her to Bahia in Brazil. She hunted for her high and low, but couldn’t find her. She stayed in Bahia for two years, until she finally caught a ship to Lisbon. She reveals to the reader, but not to Cruso, that she was the the captain's lover. But during the voyage, the sailors mutinied and killed the captain. They set Susan adrift in a small boat. This is how she landed on the island with Cruso.
Cruso is stubborn and irrational. He has no idea how long he’s been on the island because he’s kept no record. It could be months; it could be decades. He has also lost track of everything that happened to him and Friday before being on the island. Susan is appalled that he has never tried to keep any record. He mixes up all his stories. She has no idea what’s true or not. He reveals however that Friday doesn’t speak because he has no tongue. He gets Friday to open his mouth and show Susan. His tongue was cut out either by slavers or by Cruso himself. Cruso blames the slavers. Susan doesn’t know how to look at Friday after learning this. She gets nervous around him.
Susan spends a year on the island with Cruso and Friday. She sleeps with Cruso once. He falls into bouts of fever. He spends his days leveling useless terraces all over the island. There is nothing to plant on the terraces and they have no purpose, but he labors over them as though they are the greatest necessity. Friday catches fish. They don’t go hungry. They live in a small shack. The winds get terrible.
Finally, an English ship comes by and they are rescued – or at least, Susan is rescued. Cruso is experiencing a fever at the time and is carried on board against his will. Friday tries to run and hide, but Susan insists that they must get him; she believes it’s the humanitarian thing to do. They travel back to England but en route Cruso dies and Friday becomes Susan’s charge.
In England, Susan is desperate and Friday is dependent on her. He is terrified by London. Susan seeks out a famous writer named Daniel Foe and persuades him to turn her story of the island into a book. Foe isn’t interested in Cruso and Friday. Their island existence seems tedious to him. He is much more interested in Susan’s time in Bahia. He wants to hear how she survived. He knows that it’s very difficult for a woman to survive alone. But she refuses to tell him (or the reader) what happened to her there.
Foe is in debt and one day abandons his house to get away from creditors. Susan moves into his abandoned house with Friday. They eat carrots from the garden and she teaches him to garden. She sells off Foe’s belongings for money. Friday finds Foe’s robes and takes up dancing in them. He twirls endlessly, with nothing on underneath the robes. One day while he’s dancing the robes spin open and she sees that it’s not only his tongue that was cut off. Friday is also castrated.
Susan grows more and more curious about Friday. She speaks to him, confesses all kinds of things and shares her thought on him and on language. She feels bad for bringing him to England and decides to take him back to Africa. She has no money but walks with him from London to Bristol. They sleep in barns and under hedges. They get chased down by drunken soldiers. They get called gypsies. They’re muddy and filthy. They reach the ports in Bristol and she attempts to put Friday on a ship bound for Africa but realizes that there’s no hope: he will get sold back into slavery if she sends him out on any ship.
She brings Friday back to London and they find Foe. He has been too busy to write her book; but mostly he wants to know about what happened to her in Bahia. She and Foe argue over what the real story is. Foe feeds her and Friday and they debate the true story. She believes that the story that needs to be told is on the island and it has to do with Friday. It has to do with his tongue. The story that Friday isn’t able to tell is the story they must tell. Foe resists this, and pushes Susan to tell her scandalous affairs. She refuses. She tells him about Friday’s castration. They discuss how Friday thinks. Foe wants to teach Friday to write. He gives him a slate and Friday draws o’s all over it. Friday sleeps in the alcove of Foe’s room and Susan gets in Foe’s bed. They sleep together. His motion reminds her too much of Cruso, so she gets on top of him, frightening him at first. Then she tells him to think of her as his Muse. They lie in bed talking about Friday.
A dream-like sequence ensues in which Susan returns to the beginning of the story, where she swims toward the island. Buts instead of going ashore, she goes under the water to a wreck of a ship. She finds Friday chained up, sinking into the sand. She meditates on his body being his story. His voice is like the water that moves through his body, out his mouth, reaching every shoreline.
