The cast is made up of Carrie, a successful sculptor; Paul, a banker; and Carrie Younger and Paul Younger, their alter egos -- memories of their younger lives when they loved each other. (They had even talked of marriage.) But that early love went awry.
Carrie and Paul each married someone else. Carrie's marriage ended in divorce. When she read of Paul's wife's death, Carrie sent him a sympathy note, and now --years since they last saw each other-- he shows up unannounced at her door... accompanied by the memory of when he was Paul Younger.
Paul Older tells Paul Younger not to interfere. "I won't if you promise not to make a fool of yourself," the younger retorts. When Carrie Older hesitates while opening the door, Carrie Younger urges her on.
Don't all of us at one time or another think of our early loves? What would happen if one of those early loves knocked at your door? The play poses the question: Do people change as they mature? Can they change?