Charlotte Jameson agrees to marry her millionaire boss Howard. Charlotte already has a boyfriend named Mark, but agrees to the marriage at Mark's behest, figuring that Howard has only a year to live. On their wedding day, Howard presents Charlotte with a pearl necklace which he says he'd like to add to with one more pearl for every year of their marriage.
One year later, Howard is still alive. To commemorate their anniversary, Howard presents her with another pearl. Charlotte calls Mark, but he urges her to stay with Howard since he won't live forever. Five years go by, and Charlotte realizes that Mark has been fooling around. Angrily, she storms off, vowing never to share her money with him.
Ten years pass and Howard is still alive, but sick. Mark see Charlotte and hopes to resume their former relationship. She is not interested, but she does take a liking to Mark's son and the two form a friendship. After the summer ends, she and Howard agree to pay for Mark's son's education.
After twenty five years of marriage, Howard gives Charlotte his last pearl, completing the strand. He dies shortly thereafter. When Mark visits Charlotte he is outraged. She is going to get married, but to Mark's son, who is now twenty-two years old.