The Jazz Age is in full swing, but it's passing Casiopea Tun by. She's too busy scrubbing floors in her wealthy grandfather's house to do anything more than dream of a life far from her dusty, small town in southern Mexico. A life she could call her own.

This dream is impossible, distant as the stars - until the day Casiopea opens a curious chest in her grandfather's room and accidentally frees an ancient Mayan god of death. He offers her a deal: if Casiopea helps him recover his throne from his treacherous brother, he will grant her whatever she desires. Success will make her every dream come true, but failure will see her lost, for ever.

In the company of the strangely alluring god and armed only with her wits, Casiopea begins an adventure that will take her on a cross-country odyssey, from the jungles of Yucatn to the bright lights of Mexico City and deep into the darkness of Xibalba, the Mayan underworld.