Mexican culture is an integral aspect of Ghosts as its protagonist, Cat, and her sister, Maya, discover their own rich heritage (Discovering One’s Heritage). The story takes place in a town with a Spanish name, Bahía de la Luna, or Bay of the Moon. The town’s name helps illuminate the events that take place there as well as its history of Mexican immigrants. Many of the town’s inhabitants are also of Mexican heritage and place great importance on maintaining their cultural traditions. Día de los Muertos, or the Day of the Dead, is a special celebration that takes place November 1 and 2, but in the novel, it also includes Halloween.

Despite its name, this celebration honors life, tradition, and family. It upholds the ideas of the value of life, its temporary nature, and the eternal bonds of family that tie generations together. The celebration also encourages embracing rather than fearing death, and this helps Cat learns to change her perspective. Day of the Dead has Indigenous Mexican roots; it came to be celebrated on the dates of All Saints Day and All Souls Day as Catholic traditions syncretized with Indigenous practices following the Spanish conquest.