Josette is the reincarnation of the Greek goddess Britomartis, who fell in love with a Welsh prince and demigod named Arthegall ap Tyr, when she saw him in a mirror. They married, gave up their godhoods, and had a son and daughter.
As a human, Jo had gone bankrupt divorcing her cheating husband and was about to lose her home, so she took a job from her cousin Selena Laurens. She was supposed to record the investigation of a haunted house, but she fell through a mirror into the fey realm Terre Derrière le Voile. She would have been slaughtered by demons, but Cadegan rescued her.