Gregor Samsa, a traveling salesman, wakes up in his bed to find himself transformed into a large insect. He looks around his room, which appears normal, and decides to go back to sleep to forget about what has happened. He attempts to roll over, only to discover that he cannot due to his new body—he is stuck on his hard, convex back. He tries to scratch an itch on his stomach, but when he touches himself with one of his many new legs, he is disgusted. He reflects on how dreary life as a traveling salesman is and how he would quit if his parents and sister did not depend so much on his income. He turns to the clock and sees that he has overslept and missed his train to work.
Gregor’s mother knocks on the door, and when he answers her, Gregor finds that his voice has changed. His family suspects that he may be ill, so they ask him to open the door, which he keeps locked out of habit. He tries to get out of bed, but he cannot maneuver his transformed body. While struggling to move, he hears his office manager come into the family’s apartment to find out why Gregor has not shown up to work. He eventually rocks himself to the floor and calls out that he will open the door momentarily.
Through the door, the office manager warns Gregor of the consequences of missing work and hints that Gregor’s recent work has not been satisfactory. Gregor protests and tells the office manager that he will be there shortly. Neither his family nor the office manager can understand what Gregor says, and they suspect that something may be seriously wrong with him. Gregor manages to unlock and open the door with his mouth, since he has no hands. He begs the office manager’s forgiveness for his late start. Horrified by Gregor’s appearance, the office manager bolts from the apartment. Gregor tries to catch up with the fleeing office manager, but his father drives him back into the bedroom with a cane and a rolled newspaper. Gregor injures himself squeezing back through the doorway, and his father slams the door shut. Gregor, exhausted, falls asleep.
Gregor wakes and sees that someone has put milk and bread in his room. Initially excited, he quickly discovers that he has no taste for milk, once one of his favorite foods. He settles himself under a couch and listens to the quiet apartment. The next morning, his sister Grete comes in, sees that he has not touched the milk, and replaces it with rotting food scraps, which Gregor happily eats. This begins a routine in which his sister feeds him and cleans up while he hides under the couch, afraid that his appearance will frighten her. Gregor spends his time listening through the wall to his family members talking. They often discuss the difficult financial situation they find themselves in now that Gregor can’t provide for them. Gregor also learns that his mother wants to visit him, but his sister and father will not let her.
Gregor grows more comfortable with his changed body. He begins climbing the walls and ceiling for amusement. Discovering Gregor’s new pastime, Grete decides to remove some of the furniture to give Gregor more space. She and her mother begin taking furniture away, but Gregor finds their actions deeply distressing. He tries to save a picture on the wall of a woman wearing a fur hat, fur scarf, and a fur muff. Gregor’s mother sees him hanging on the wall and passes out. Grete calls out to Gregor—the first time anyone has spoken directly to him since his transformation. Gregor runs out of the room and into the kitchen. His father returns from his new job, and misunderstanding the situation, believes Gregor has tried to attack the mother. The father throws apples at Gregor, and one sinks into his back and remains lodged there. Gregor manages to get back into his bedroom but is severely injured.
Gregor’s family begins leaving the bedroom door open for a few hours each evening so he can watch them. He sees his family wearing down as a result of his transformation and their new poverty. Even Grete seems to resent Gregor now, feeding him and cleaning up with a minimum of effort. The family replaces their maid with a cheap cleaning lady who tolerates Gregor’s appearance and speaks to him occasionally. They also take on three boarders, requiring them to move excess furniture into Gregor’s room, which distresses Gregor. Gregor has also lost his taste for the food Grete brings and he almost entirely ceases eating.
One evening, the cleaning lady leaves Gregor’s door open while the boarders lounge about the living room. Grete has been asked to play the violin for them, and Gregor creeps out of his bedroom to listen. The boarders, who initially seemed interested in Grete, grow bored with her performance, but Gregor is transfixed by it. One of the boarders spots Gregor and they become alarmed. Gregor’s father tries to shove the boarders back into their rooms, but the three men protest and announce that they will move out immediately without paying rent because of the disgusting conditions in the apartment.
Grete tells her parents that they must get rid of Gregor or they will all be ruined. Her father agrees, wishing Gregor could understand them and would leave of his own accord. Gregor does in fact understand and slowly moves back to the bedroom. There, determined to rid his family of his presence, Gregor dies.
Upon discovering that Gregor is dead, the family feels a great sense of relief. The father kicks out the boarders and decides to fire the cleaning lady, who has disposed of Gregor’s body. The family takes a trolley ride out to the countryside, during which they consider their finances. Months of spare living as a result of Gregor’s condition have left them with substantial savings. They decide to move to a better apartment. Grete appears to have her strength and beauty back, which leads her parents to think about finding her a husband.
