Mrs Dalloway is not your typical day-in-the-life story, but it is a day-in-the-life story – a revolutionary one at that. It covers one day for Clarissa Dalloway (with some other central characters, too) as she prepares for a big party that will take place that evening.
As the novel begins, Clarissa strolls through Westminster, her neighborhood in London, on her way to a flower shop. Along the way, a few big things go down: she runs into an old friend named Hugh Whitbread, an explosion comes from a diplomatic car on its way to Buckingham Palace, and an "aeroplane" does a little skywriting. (Wow, that’s way more than what typically happens to us on the way to get flowers.)
When she gets back from her errand, an old friend and former suitor, Peter Walsh, shows up unexpectedly. They’re happy to see each other, but there’s still some tension. Peter is clearly still in love with Clarissa, and she feels like he judges her for the decisions she’s made – among them marrying the conservative but loyal Richard Dalloway (instead of him). Numerous flashbacks – including one of Clarissa's kiss with a girl named Sally – fill in the story as it happened years ago at her family’s country home, Bourton. Feeling desperate over his own unfulfilling life, Peter gets weepy and asks Clarissa if she really loves Richard. Before she can answer, Elizabeth (her daughter) interrupts, and Peter heads out to Regent's Park.
We then move to the perspective of Septimus Warren Smith, a shell-shocked World War I veteran who saw Evans, his friend and officer, killed in war. Septimus' wife, Lucrezia, is trying to distract him as they wait for an appointment with Sir William Bradshaw, a mean old psychiatrist.
The third person omniscient narrator takes us back to Septimus’ life before the war: he was an aspiring poet, read Shakespeare, and loved Miss Isabel Pole. After the war and Evans' death, Septimus becomes emotionally numb – he can't feel anything. On a total whim, he becomes engaged to Lucrezia, whose home he’s staying at in Milan, Italy. Back in the present day, Septimus is driven deeper into madness, including some crazy hallucinations. Lucrezia is also miserable, homesick for Italy, and tired of taking her husband to various soulless doctors. Whereas Dr Holmes thinks Septimus is just "in a funk," Dr Bradshaw diagnoses that he "lacks Proportion." Neither acknowledges the fact that the war has impacted Septimus (which seems pretty obvious to us).
While Clarissa rests and prepares for the party, Richard has lunch with the impressively rich and British upper crust Lady Bruton. After lunch, Richard wants to go home and tell Clarissa he loves her, but he cops out and just gives her flowers instead. Clarissa actually cherishes the independence she has in her marriage, knowing that she could never have that with Peter. In the meantime, Clarissa’s daughter goes off shopping with her friend Miss Kilman, whom Mrs Dalloway hates. And by hates, we mean despises, loathes, and absolutely cannot stand.
Meanwhile, Septimus and Lucrezia wait at their apartment for Sir William Bradshaw, who is coming to take Septimus to a psychiatric home. The couple shares a rare moment of joy, but before Bradshaw enters the apartment, Septimus throws himself out the window and is impaled on the fence outside. He would rather die than have the doctor steal his soul. Yikes.
When Clarissa’s party begins, she circulates, making sure to pay attention to every guest – especially the prime minister (um, yeah, we’d do the same). Peter and Sally patiently await some attention from Clarissa as they talk about their memories of Bourton. A late arrival, Sir William Bradshaw, shows up with his wife, who announces that Septimus has killed himself. Clarissa is annoyed that Lady Bradshaw mentioned death at her party, but she is envious of Septimus’ ability to embrace the moment. Finally, she returns to the party and her appearance fills Peter’s heart with joy.