London, summer 1923. Clarissa, MP Richard Dalloway's wife, sets out on a beautiful morning; she's shopping for flowers for her party that evening. At the same time Septimus Warren Smith, a young man who survived the battlefields of Europe, is suffering from a nightmarish delayed-onset form of shell-shock. Clarissa's nearly-grown daughter is distant, and preoccupied. In the course of one day, Peter, Clarissa's passionate old suitor, returns from India and is invited to her party; Septimus commits suicide; Clarissa relives a day in her youth (and her reasons for her choice of a life with the reliable Richard Dalloway).