Gregor Samsa wakes up one morning from troubled dreams to discover that he has transformed in his bed into a horrible vermin with a domed brown belly, numerous pitifully thin waving legs, and an armour-like back. Initially thinking the situation is a temporary absurdity and dwelling on the exhausting nature of his career as a travelling salesman, he attempts to return to sleep. However, his physical transformation prevents him from rolling onto his usual side, and his efforts only result in a mild, unfamiliar pain. Reflecting on his exhausting lifestyle, his difficult boss, and the family debt he is working to pay off, he notices the time is nearly quarter to seven, meaning he has missed his train.
As Gregor struggles to process his situation, his mother knocks on his door, prompting him to answer, but his voice has transformed into a painful, uncontrollable squeaking mixed with an unclear echo. Although his mother is initially satisfied by his brief reassurance, his father and sister soon grow concerned and plead for him to open the door. Locked inside by his own cautious habit, Gregor focuses on getting out of bed without being disturbed, despite his lack of control over his multitude of tiny legs. After several difficult attempts, he painfully hits his head against a bedpost and realizes that moving his new body requires careful patience and the avoidance of sudden, reckless motions.
While Gregor contemplates his next steps and listens to the morning fog outside, the doorbell rings and the chief clerk himself arrives to investigate his absence. Alarmed and upset by the unexpected visit from his boss's representative, Gregor hears his mother defending his strong work ethic to the chief clerk while his sister quietly weeps in an adjoining room. When his father impatiently asks if the chief clerk can enter, Gregor refuses, plunging the household into a tense and emotional silence. The chief clerk then raises his voice through the door, rebuking Gregor for barricading himself inside, causing unnecessary concern to his parents, and exhibiting an unprecedented failure in his business duties.
Desperate to salvage his reputation and reassure the terrified chief clerk, Gregor Samsa ignores his bizarre physical transformation, pulls himself up using a chair, and pleads for his job from inside his bedroom. Hearing his strange, animal-like voice and his refusal to open the door, his mother panics and sends his sister Grete for a doctor, while his father urgently summons a locksmith. Determined to prove he is capable and cooperative, Gregor uses his strong jaws to turn the key in the lock, finally opening the door and revealing his monstrous insectoid form to the astonished household.
The sudden sight of Gregor provokes immediate terror and chaos. The chief clerk backs away in horror before fleeing down the stairs in a panic, while Gregor's mother collapses unconscious among the scattered breakfast remains, spilling coffee across the carpet. His father, overwhelmed by anger and panic, seizes the chief clerk's forgotten walking stick and newspaper, and begins forcefully and relentlessly driving Gregor back toward his bedroom with aggressive hissing and stamping feet.
Unable to reverse smoothly and fearing his father's wrath, Gregor struggles to turn his wide body around in the cramped corridor. When he finally tries to squeeze back through the narrow doorway, his body wedges sideways against the frame, painfully scraping his flank and leaving brown flecks on the white wood. Trapped and unable to move further on his own, his legs dangle helplessly as his father forcefully shoves him the rest of the way into the room, cutting off any remaining hope of escape.
With a final, heavy shove from behind, Gregor's father forces him completely through the narrow doorway and sends him flying deep into his room. The severe impact leaves Gregor bleeding heavily as he lands on the floor.
His father then uses the walking stick to slam the door shut behind him. Finally, silence settles over the flat as the chaotic confrontation comes to an abrupt and isolated end.