Each of the three protagonists in The Hours has a different goal, but all want to arrive at the same place; happiness and satisfaction in their lives.
Virginia Woolf, the real-life author who inspired the book with her novel Mrs. Dalloway, wants to write and create great art, but fears the mental illness that has troubled her on and off her entire life. When she is writing, she uses events from her own life to spur characterization, and is highly aware of her role in society; she finds herself stifled at home, scorned by male critics (who are exemplified by young boys who she imagines are laughing at her) and although she loves her husband deeply, she is so terrified of her depression and "madness" that she commits suicide rather than experience it again.
Laura Brown is a Los Angeles housewife in the 1950s, trying to keep her family happy while yearning for something more in life. While reading Woolf's Mrs. Dalloway, Laura experiences an epiphany and attempts to become more of a perfect housewife and mother, baking a birthday cake for her husband that turns out mediocre instead of transcendent. Her love of her family becomes oppressive in her mind, and she eventually abandons them.
Clarissa Vaughn is a New York socialite who is readying a party to celebrate the life of a dear friend, Richard, who is dying of AIDS. Despite her emotional ties to Richard and her desire to honor him, he is overcome with depression that he has failed in his life and his art. Clarissa wants the party to be entirely in benefit of Richard's life as an artist and loving man, and her realization that her tryst with Richard years back was in fact a genuine love affair leads to tragedy when he commits suicide; she later accepts that while he is gone, the happy moments he shared with others will continue in their memories.