In many lives there is a crossroads. We make our choice, and follow it down to the present moment. Still inside of us is that other person, who stands forever poised at the head of the path not chosen. "Mrs. Dalloway" is about a day's communion between the woman who exists, and the other woman who might have existed instead.
The film's heroine muses that she is thought of as "Mrs. Dalloway" by almost everybody: "You're not even Clarissa any more." Once she was young and fair, and tempted by two daring choices. Peter would have been a risk, but he was dangerous, and alive. Even more dangerous was Sally, with whom flirtation threatened to develop into something she was unwilling to name. Clarissa took neither choice, deciding instead to marry the safe and sound Richard Dalloway, of whom young Peter sniffed, "He's a fool, an unimaginative, dull fool." Now many years have passed. Mrs. Dalloway is giving a party. The caterer has been busy since dawn, the day is beautiful, and she walks through Hyde Park to buy the flowers herself. So opened Virginia Woolf's famous 1923 novel, which followed Clarissa Dalloway for a day, using the new stream-of-consciousness technique that James Joyce was experimenting with. We will follow her through until the end of her party, during a day in which no one she meets will know what she's really thinking: All they will see is her reserved, charming exterior.
The novel stays mostly within the mind of Clarissa, with darts into other minds. Film cannot do that, but "Mrs. Dalloway" uses a voice-over narration to let us hear Clarissa's thoughts, which she never, ever shares with anybody else. To the world she is a respectable 60-ish London woman, the wife of a cabinet official. To us, she is a woman who will always wonder what might have been.
Vanessa Redgrave so loved the novel that she commissioned this screenplay by Eileen Atkins, an actress who has been involved in a lot of Woolf-oriented stage work. Redgrave of course seems the opposite of a woman like Clarissa Dalloway, and we assume she has few regrets. But we all wonder about choices not made, because in our memories they still glow with their original promise, while reality is tied to the mundane.