Without the protection of parents, Zuleika Dobson has had to make her own way in the world. Having found success on the stage, she delights in the attention of men. Visiting her grandfather in the male-dominated domain of the University of Oxford seems the perfect way to fill time between engagements.
In Edwardian Oxford, Zuleika’s beauty is soon noticed by the university’s gentlemen, but she considers it an indignity to fall in love with a man who could be enslaved by adoration of her. Instead, she seeks a man who finds her resistible; she thinks she has found such a man in a young duke.
However, much to Zuleika's horror, the Duke falls in love with her, prompting her to reject him as too willing a suitor. In a final attempt to win Zuleika, the Duke tells her that he will commit suicide in her honour. Zuleika is thrilled at the prospect of a man dying for love of her, and she encourages him to do so.
To further complicate matters, the other undergraduates learn of the Duke’s intention and, ultimately, all the undergraduates resolve to drown themselves in the river after the summer boat races. Although the Duke comes to regret his impulsive promise to die for Zuleika, he understands that his honour demands he go through with it. He dresses in his robes of state and sets out for the river. After the races he drowns himself, and all of Oxford's fine young undergraduates follow his example.
Contrary to her expectations, Zuleika is saddened by the mass drowning, and she temporarily resolves to lock herself away in a convent. However following a conversation with her grandfather, who has not noticed the absence of the undergraduates in his charge, she decides that it would be better to remain in the world. But with Oxford now devoid of suitors, it occurs to her that this would be a good time to visit Cambridge.