Cassie Blake is a teenage girl from California. Her mother dies in a fire, causing Cassie to move to a small town in Washington, called Chance Harbor, to live with her grandmother, Jane Blake. When she begins her new high school, Cassie quickly meets a new group of friends who tell her that they have all come from a line of witches, and they have been waiting for Cassie to join them to finalize their new generation of a "Secret Circle".