One day near the beginning of World War II, Virginia Woolf leaves a note for her husband, Leonard, and sister, Vanessa. She then goes out to a river with stones in the pockets of her jacket to drown herself.
Years later, two women (Laura and Clarissa) each deal with problems in their lives similar to those that the titular character Mrs. Dalloway faces in Virginia Woolf’s novel Mrs. Dalloway. The story shifts between three timelines, following Virginia’s life in a suburb outside London in 1923 as she writes Mrs. Dalloway, Laura’s life in Los Angeles in 1949 as she makes a cake for the birthday of her husband (Dan), and Clarissa’s life near the turn of the millennium in New York City as she prepares a party before an awards ceremony for her friend and former lover, Richard (whose nickname for Clarissa is “Mrs. Dalloway”).
Clarissa spends her morning buying flowers in preparation for Richard’s party. Richard is a famous writer who is best known for his poetry, though he also wrote one long novel about a suicidal housewife. Many people interpret the novel as being inspired by Clarissa. Richard is about to receive an award called the Carrouthers prize, and Clarissa has organized a party beforehand. As Clarissa walks around New York City, she runs into some of her and Richard’s mutual acquaintances, and she begins to think back to when she was in college and attempted a relationship with Richard while he was also in a relationship with Louis. The situation with didn’t work out, and Richard and Louis spent many years together while Clarissa went on to live with a new partner named Sally, with whom she has a daughter (Julia). Now, Richard has left Louis and lives alone in declining health due to the toll that AIDS has taken on him. Clarissa serves as his primary caregiver.
Meanwhile, back in the 1920s, Virginia spends her morning writing part of Mrs. Dalloway before preparing for a visit from her sister, Vanessa. Virginia struggles to write much because she fears that too much exertion will bring back her painful headaches. These headaches are the reason why Virginia’s husband, Leonard, insists that they must live out in the peaceful suburb of Richmond, even though Virginia longs to return to the excitement of living in London.
In 1949, Laura, pregnant with her second child, sleeps in late on the morning of Dan’s birthday, exhausted from staying up late to read Mrs. Dalloway the night before. She wants to give Dan a perfect birthday, so she sets to work making a cake for him with their son, Richie (Clarissa’s friend Richard as a child). Making the cake with Richie seems to temporarily help Laura overcome her anxieties, but when the cake is done, she fears it isn’t good enough and throws it out to start over again.
In Clarissa’s timeline, Clarissa finally makes it to Richard’s apartment and finds him anxious about attending the party and awards ceremony. Clarissa can tell how much Richard’s mental state has been affected by his illness—he has lost much of the wit and sharpness that used to define him. She promises to come by early to help him get dressed and ready for his party.
Back in the 1920s, Virginia wants to serve her sister the best possible refreshments, so she sends her servant Nelly on a trip to London and back. But, as it turns out, Vanessa arrives earlier than expected, throwing off Virginia’s plans. Leonard refuses to leave his work until the time when Vanessa originally promised to come. As Virginia is entertaining Vanessa, her children discover a dying bird outside and hold a funeral for it.
In 1949, Laura finishes a second, better cake to replace the first one she made with Richie and gets a visit from her neighbor, Kitty. Kitty reveals that she has to go to the hospital the next day to get a growth on her uterus checked out. As Laura hugs Kitty to console her, the two of them kiss on the lips, and Laura realizes how much she desires Kitty. The women pull away suddenly, and Laura becomes flustered when she realizes Richie has witnessed the intimate moment.
Soon after, Laura begins to feel like she has to leave her house. She drops off Richie with a neighbor, claiming she has to run errands. However, Laura’s real intention is to find a place to read Mrs. Dalloway in private. Laura realizes that it’s almost impossible for her to find a place that’s suitably safe and private for her needs, so she eventually ends up renting a hotel room for the night, even though she only plans to use it for a couple hours. She feels like she’s doing something wrong.
In Clarissa’s timeline, Clarissa goes to meet Richard before his party and finds him sitting on his windowsill in a robe with one leg out the window of his fifth-story apartment. She is frightened and tries to convince Richard to come back in, but as Richard talks, he seems to be in a daze from his medication and his illness. He eventually jumps out the window, falling to his death.
In Virginia’s timeline, after Vanessa leaves, Virginia begins to feel particularly restless about her life in Richmond. She decides to take a spontaneous trip into London and even goes to the train station to buy a ticket. But when she’s waiting for her train to arrive, she runs into Leonard, and this convinces her not to take the train after all.
In 1949, Laura’s birthday party for Dan seems to be a success, although when he’s blowing out the candles, he accidentally spits on her cake. Even though Laura is relieved that the night has gone well, before she goes to bed with Dan, she looks at the sleeping pills in her cabinet and considers how killing herself wouldn’t be any more difficult than checking into the hotel was earlier that day.
Finally, the timelines intersect, with Laura, now an elderly woman, arriving at Clarissa’s apartment following Clarissa’s news about the death of Laura’s son, Richard. The flowers that Clarissa originally bought for Richard’s party now become funeral flowers. Although Richard’s party is now cancelled, Clarissa, Laura, Sally, and Julia all decide to eat some of the food because it will soon go to waste. Clarissa considers how Richard’s death has set her free from the Mrs. Dalloway nickname he imposed on her. She also considers the difficult hour ahead of her she must now face.