Ten years working at Groomtech has left Reggie Perrin feeling bored. With his wife seemingly too busy to notice him or his dissatisfaction with work, Reggie becomes enamoured with a new colleague.

Reggie and Nicola's parents are interfering in their marriage, much to Reggie's annoyance. This drives him to go just a little bit too far with the object of his desire at work - Jasmine.

Reggie thinks about becoming a teacher after thinking hard about his life. He gives a talk at Nicola's school and then asks the class to spend a day at Groomtech which ends in disaster.

Reggie is perturbed with life as his wife, Nicola, seems to prefer spending time with anyone else except him. He goes to on a business trip to Helsinki with Jasmine which gives his marriage its greatest trial so far. Chris has his eye on Reggie, too.

Reggie hates travelling to work so much that he takes up cycling. Chris desperately wants to convince the Groomtech Board that he should be chairman and asks Reggie to help. Chris invites himself to Reggie's house to work at the weekend and it causes problems for Reggie and Nicola and drives Reggie to the brink of insanity.

In the final episode of the series, Reggie looks over the brink at his life.