A summary of the first episode, originally aired on 8th September 1976.
On a hot Tuesday, Reginald Iolanthe Perrin sets out for work as usual, disconcerted by his association of his mother-in-law with a hippopotamus. Taking the train, he fails to complete the crossword as usual. Arriving at Sunshine Desserts, eleven minutes late, he dictates a letter to his secretary Joan but is interrupted by a phone call from his boss, CJ, who insists on seeing him that afternoon. Also at the meeting are Reggie's two junior sales managers, Tony Webster and David Harris-Jones. CJ's instructions about Reggie's new 'exotic ices' project are interrupted by Reggie's fantasies about a romantic tryst with Joan. CJ asks whether Reggie is losing his drive, but is vaguely reassuring. Reggie returns home eleven minutes late. When his wife Elizabeth mentions going to see her mother, Reggie has repeated visions of a hippopotamus.
The next day, Reggie's fantasies go out of control. He imagines exposing himself to an elderly neighbour. Arriving at his office, eleven minutes late, his attempt to dictate a letter to Joan is interrupted by a fantasy of making love to her on top of his desk. Concerned by his inability to concentrate, he consults the firm's doctor, who is more worried about his own flagging libido. Reggie discusses his children Mark and Linda and confesses to fantasies about nude sportswomen. The doctor merely offers Reggie two aspirins.
In the afternoon, Reggie hosts an ice-cream tasting session, but upsets CJ by leaving his flies undone and referring to a crisis in the firm. When the computer fails before giving the results of the tasting session, Reggie is irrationally upset and goes to be sick. That evening, he calls Elizabeth's mother a hippopotamus.
On Thursday, Reggie says that he feels that nothing in his life matters and that he is determined to rebel. Arriving late at a sales meeting, he suggests ludicrous advertising slogans and is deliberately offensive. He adjourns the meeting early, saying that he can't be bothered with it any more. Avoiding his usual pub lunch, he goes to an Italian restaurant, where he eats ravioli for each course and harasses the couple lunching opposite. In the afternoon, he dictates a letter to British Rail, asking why they don't re-time all their trains to arrive eleven minutes late. At home in the evening, he expresses frustration at the pointlessness of his life and issues a scream of desperation.
