"Key of Valor" by Nora Roberts is the third book in Roberts' Key Trilogy. The basis of the trilogy is that three women have been asked by ancient gods to help free three demigoddesses trapped in glass boxes by an evil sorcerer.

The main character in this part of the trilogy is Zoe McCourt. Zoe and her two close friends, introduced in "Key of Light" and "Key of Knowledge," have decided to open a business named Indulgence. Each woman has her specialty.

The story begins with Zoe's history. Zoe was raised by a hardened mother and alcoholic father. When Zoe was twelve, her father took off with another man's wife. Zoe's mother, Crystal, became harder than ever and Zoe became caretaker to the family. In order to make ends meet Crystal opened a beauty salon in her home. Zoe worked there with her on a daily basis while minding the children. Zoe eventually meets a falls in love with a local rich boy and becomes pregnant. The boy's family accuses Zoe of terrible things and leave Zoe to fend for herself. Her only compensation is a check for $5,000. Zoe moved out of her town and eventually out of West Virginia altogether. Zoe lands in a town in Pennsylvania named Pleasant Valley.

This book picks up ten years later, when Zoe is 26 years old. This story begins where the previous book of the trilogy - "Key of Knowledge" left off.

Various characters from the previous book are introduced - Malory Price, Dana Steele, Jordan Hawke, Bradley Vane, and Flynn Hennessy. Also included are Rowena and Pitte, otherworldly chaperones to the Daughters of Glass and Kane, an evil sorcerer, who wants to stop the three women from finding the third and final key.

The women work hard at readying Indulgence for its opening day. Meanwhile, it is Zoe's turn to accept the challenge at finding the third and final key to release the Daughters of Glass. Although Zoe will have people to help her, the main quest will be on her shoulders.

Bradley Vane is in love with Zoe and will do anything to help her. However, Zoe has to learn to accept help and realize that there are people who do care for her and want what is best for her and her son, Simon.

The people in charge of the quest are Rowena and Pitte, ancestors who are responsible for the daughters' predicament. They have offered money to the triad to save the demigoddesses.

Zoe's quest involves examining her past thoroughly and revisiting each major choice that she has made. Zoe eventually learns that she has made the right choices for herself, from keeping Simon to moving to Pennsylvania to opening Indulgence to falling in love. It is Zoe's acceptance that allows her to find the key. Zoe must face off with Kane, the evil sorcerer. Kane, whose soul is made up of pain and sorrow, has no chance against Zoe's determination to live a happy life. Zoe slays Kane with the help of a demigoddess and prepares for a bright future. The demigoddesses are released from their prison and Rowena and Pitte are permitted to return home after 3,000 years.