After her mother's death in 2022, Manon Perrault finds a mermaid necklace given to her as a child that belonged to her 8th great grandmother, Marie Pontonnier. Marie migrated in 1656, at age thirteen, from France to Canada. The mermaid necklace is more than a keepsake; it is a magical portal through time. The orphaned Marie agreed to marry and populate Nouvelle France in exchange for her ship passage as a 'Fille marier.' On her wedding day, a jealous suitor cast a spell that made her husband impotent and resulted in a conviction of witchcraft. After three years with no children, the Church annulled her first marriage. Marie remarried, but her second husband was murdered soon after. A month after the birth from her second marriage, Marie married for the third time and bore ten more children. Marie's descendant Manon, a professor of marine ecology, is married with no children, although that is her fervent desire. Manon uses the necklace to transport herself through time to visit Marie. Marie's advice to "follow your heart" helps Manon and gives her an in-depth perspective on life and death. The mermaid necklace serves as the threshold to connect their lives and as a meaningful symbol for both. Marie Pontonnier is a historical figure who was one of 262 "Filles marier" that migrated from France to Canada between 1634 and 1662. In "The Mermaid Necklace," Marie's life is depicted as much as possible based on historic dates, names, and information. However, the blank spaces are filled by the author's imagination. Marie's descendant in the novel, Manon Perrault, and everyone else connected with Manon are fictitious.