William Bloom recalls one of his last car trips with his father, Edward Bloom. They stop by a river, and Edward wades in to the water, remembering his childhood. William sees Edward as a wild creature who’s both young and old, and Edward becomes a myth.
William begins narrating the story of his father’s life. Edward is born during a drought in Ashland, Alabama, at precisely the same time as a colossal thunderstorm erupts. Growing up, Edward has a way with animals. It seems like he can communicate with them, and they follow him around. When Edward is nine, a huge snowstorm blankets Alabama and buries Edward’s house. He sleeps in a tree and walks by a man frozen in a block of ice on his way to school. Edward grows so quickly that his bones can’t keep up, and he’s confined to bed for a time. He uses the time to read every book in his hometown. William thinks that Edward is already a big fish.
William jumps forward in time to describe his father’s death. Dr. Bennett, the trusted family doctor, comes out of the guest room and says there’s nothing he can do. William and his mother, Sandra, have been expecting this, as Edward’s been ill for some time. William explains that Edward has been an “itinerant” father who traveled a lot for work and made pitstops at home in between his adventures. Each time, Edward would quickly become frustrated when he was home and always yearned to be back on the road. Back in the present, William goes in to the guest room, and Edward says he feels bad for missing a lot of William’s life. Edward explains that he wanted to be a great man, a big fish in a big pond. Edward starts to tell William about a two-headed lady, but William cuts him off, saying he doesn’t want to hear about her again. Edward quips that he’s actually talking about the two-headed lady’s sister, and William is immediately drawn into the story.
William switches back to narrating Edward’s earlier life. One day, Edward is relaxing by the river when he sees a beautiful river girl bathing in the water. A snake is swimming towards her, so Edward jumps in to grab it. Edward turns around so the river girl can put her clothes on, but when he turns back, she’s gone. The snake has turned into a stick, though it somehow still seems to swim away.
One of William’s favorite stories about Edward’s youth is the story of Karl the Giant. Karl is a strapping young boy with an immense appetite. When Karl is fourteen, he finds his way to Ashland and starts eating everything in sight. Edward seeks out Karl to resolve the situation. Karl is menacing at first, but soon starts crying, explaining that he’s always hungry. Edward promises to teach Karl how to cook and farm so that he doesn’t have to steal from others, and Karl ends up becoming one of the most successful farmers in Ashland. One day, there’s a flood in Ashland that buries half the town under a lake where giant catfish supposedly swim. Edward goes fishing for one of these catfish and gets pulled underwater. Edward sees all the people whose homes were flooded, living as normal with little air bubbles escaping from their mouths as they talk to each other.
When Edward is seventeen, he decides to leave town. He must first pass through the place that had no name, where many people get stuck, unable to move forward. The weather grows ominously gloomy as Edward approaches the town. It’s a barren place where disfigured people with missing fingers wander around, looking lost. An old man named Wiley greets Edward and shows him around. Edward notices that the air is damp, and Wiley explains that the dampness is the residue of people’s forgotten dreams. Suddenly, a fierce dog (named Dog) emerges and heads for Edward. Wiley explains that Dog is a sort of gatekeeper, as he instructs a terrified Edward to put his hand out. Dog stops growling and nuzzles Edward’s hand instead. Wiley looks disappointed but whisks Edward off to the Good Food Cafe. A man even older than Wiley warns Edward not to face Dog again, and people start crowding around Edward urging him to stay. Suddenly, they back off—Dog is approaching. Edward leaps past Dog and runs out of the place that had no name. The sky brightens, and Edward and Dog run alongside one another. They reach a lake, and Dog nuzzles Edward warmly before laying down. In the distance, Edward sees the river girl waving to him.
Edward’s business partner, Jasper Bloom, tells the next part of the story. That night, Edward is robbed, beaten, and left for dead by a pair of thugs, but he walks on, ready for whatever lies ahead. Edward arrives at a country store run by an old man named Jim Benson, who offers Edward medical assistance. Edward doesn’t want to accept charity, so he grabs a broom and starts sweeping the floor, dragging his broken leg behind him. Edward collapses, and the Benson family crowd around him before he wakes, briefly, to utter one word: “Advertise!” Edward ends up staying with the Bensons for a while, and through his ingenious advertising, turns the Benson’s failing store into a success.
William resumes narrating and says that Edward decides to go to college in Auburn. Edward meets an old lady who explains that some boys stole her glass eye, so Edward vows to return it to her. Edward finds the boys in an old barn, sitting around the glass eye. Edward convinces them to loan him the eye, though the gang leader warns Edward that if he doesn’t return the eye in the morning, they’ll gouge out of Edward’s eyes. Edward is terrified and stays up all night wondering what to do. In the morning, Edward returns to the barn, bringing the old lady with him, who is now wearing the eye. She stares at all the boys in turn, and they run away, terrified. Edward begins his studies and the boys never bother him again.
William jumps forward once again to Edward’s death. In the guest room, William asks Edward if he believes in God. Edward deflects with a joke. William is frustrated—he just wants Edward to be straight with him for once. Edward says he doesn’t know what he thinks about God and he’d rather share a joke than a bunch of doubts, because at least jokes make people laugh.
William resumes narrating Edward’s life, now turning to Edward’s courtship with Sandra. All of the boys pine over Sandra, and gang leader Don Price even proposes to her, but she goes on a date with Edward anyway. Edward woos Sandra by being himself, and they fall in love. One night, Don Price chases Edward and Sandra down. Edward tries to talk Don off the edge, but Don won’t have it, and fights Edward instead. Don loses the fight and Sandra kisses Edward, sealing their fate as lovers. Edward and Sandra elope and go to meet Sandra’s senile parents, before settling in Alabama.
Edward faces three labors in Alabama. His first labor is cleaning out animal cages in a veterinary. His second labor is working as a lingerie clerk in a department store, where he has to convince a customer named Muriel Rainwater that men can be good lingerie assistants. His third labor involves a wild “Helldog” that’s terrorizing the town. One night, Edward sees a toddler named Jennifer Morgan wander into the dog’s path, but he steps between them and kills the dog, pulling out its heart with his bare hands. Edward then becomes a sailor in the war, and his ship is struck by a torpedo. He almost drowns, but the river girl emerges and leads him to safety.
William jumps forward to Edward’s death, narrating it for a third time. William implores Edward to tell him just one story about his youth that’s not fabricated, but Edward explains that his stories are metaphorical before reciting yet another joke, and William leaves the room in frustration.
William switches back to narrating Edward’s life around the time that William was born. Edward is enraptured with William and makes a list of virtues that he wants the boy to embody. Edward teaches William to play catch and takes him on picnics, but he’s soon drawn away by the lure of the road, even though he loves William and Sandra. Edward returns to make “cameo” appearances in William’s life and even saves his life twice. One day, Edward climbs on the roof to look at the view and falls. Edward pretends he’s dead as a joke, and William reflects that this is how Edward wants to be remembered: as a man who makes people laugh. William acknowledges that Edward’s greatest power is his ability to make William laugh.
Shortly before he dies, Edward has a dream. In it, people crowd around the house like pilgrims, camping outside in tents. William goes outside to ask them to leave, and an old man explains that they’ve come to thank Edward for all the things he did for them, like lending them money and making them laugh. William finally understands and goes back into the house, warmly reciting a joke.
William narrates another episode in Edward’s life, when Edward is around 40 years old. Edward is very successful, but life is growing strained at home. Edward and Sandra even contemplate divorce but ultimately decide to stay together. In this period, Edward buys an entire town called Specter. There, Edward meets a young girl named Jenny Hill, and they fall in love. Edward visits Jenny sporadically, and she spends her life sitting at the window, always waiting for him. A swamp surrounds her home and soon, all that anybody can see are Jenny’s yellow eyes, glowing from deep within the swamp. Soon after, Edward returns home and explains that he has cancer. He moves into the guest room and begins swimming every day. As Edward’s condition deteriorates, the swimming pool grows swampy. One day, Edward has a stroke, and William prays for Edward to wake up and tell one more joke.
William narrates his father’s death for a fourth and final time. Edward is on life support in the hospital. William is remembering one of his father’s favorite jokes, about a man who buys a suit that’s too big for him, but he can’t tell it as well as Edward can. Suddenly, William is crying. Edward wakes briefly and says he worries about William, and that he tried to be a good father and teach William things. William tells Edward not to worry and begins reciting the joke about the man and the suit back to Edward, as Edward closes his eyes. Suddenly, Edward smiles and winks. William smuggles Edward out of the hospital and they drive to the river while Edward gurgles and pours water on himself. William carries Edward to the water’s edge, and suddenly, Edward is transformed into a fish. Edward swims off into the distance, teeming with life.