Jim Dixon is a 24-year-old junior professor of History at one of England's redbrick universities. Nearing the end of a one-year contract, he worries whether he will be kept on, as his unconventional, irreverent approach to teaching history periodically brings him into conflict with his departmental head, Professor Welch.

To Jim's surprise, Welch invites him to attend a weekend party at his house. He also asks Jim, in the absence of any other available candidate, to give a prestigious memorial lecture - but insists that the text must be a version of his own manuscript on the subject of 'Merrie England'.

On arrival at Welch's home, Jim is shown to a tiny room. He is forced to join in the communal singing of a complicated madrigal and to sit through a lengthy musical recital. He also meets Welch's son Bertrand, a pretentious novelist, and his girlfriend, Christine.

Jim escapes from the party and gets very tipsy at the local pub. Returning to the house much later, he is forced to break in, finding himself in the bedroom of Margaret, a fellow student who has designs on him. When she realises that he is only there by accident, she throws him out and he blunders around the house, eventually getting himself and Bertrand's dog drunk on cherry brandy. He falls asleep with a lighted cigarette and by morning has burnt holes in his sheet and blankets. Inventing a story about his parents visiting, he flees the house.

Back at the university, Jim helps with the arrangements for the installation of the new chancellor, Sir Hector Gore-Urquhart, who is head of a publishing firm and Christine's uncle. Thanks to Bertrand's interference, some floral displays are double-booked, resulting in their summary removal by workmen during the ceremonial procession, reducing the occasion to chaos.

At the ball that evening, Bertrand is introduced to Sir Hector, who he hopes will publish his novel. Meanwhile, Jim and Christine are becoming attracted to one another, and leave the ball together. Jim takes Christine home and she invites him inside. They kiss and, recognising their mutual feelings, agree to meet for coffee the next day.

When they meet, however, Christine tells Jim that she has given up men as a result of Bertrand's jealousy. In a temper, Jim tears up the notes Welch has given him and demands to present his own lecture. Welch forbids it, counselling him that youthful rebellion must give way to maturity.

Bertrand visits Jim in his room and they fight, leaving Jim with a black eye. Piecing together the torn pages of lecture notes, he takes pills to boost his confidence. These later react disastrously with some alcohol given him from a hip flask by the sympathetic Sir Hector. Jim is clearly drunk when he takes the stage; he loses his way and breaks the lectern. Eventually he departs from his notes completely, ridicules everything that he has been saying, and then collapses.

Next day, Jim feels he has no choice but to resign from his position. On his way to Welch's house to replace the burnt bedclothes, he is phoned by Sir Hector, who asks to see him at his London office later that week. Jim arrives at Welch's house with a new confidence and demands to speak to Christine.

When he is told that Christine has already left for the station, Jim takes Welch's battered old car and hurries to intercept her. Bertrand, Professor Welch and his wife all pursue him, arriving at the station just in time to see Jim join Christine on the train to London.