Kaileena first appears in the Sands of Time trilogy when she is attacked by Shahdee while on the Island of Time. The Prince intercedes and saves her life, and in thanks for his help, Kaileena aids the Prince in navigating the island. She criticizes, however, the goal of his mission: to change his fate and cease the Dahaka's relentless pursuit.
As they journey together, Kaileena eventually reveals that she is in fact the Empress of Time, the woman the Prince had been laboring to meet. She explains that her own fate is to die at the Prince's hands, and she hoped to avoid that fate by plotting to kill the Prince.
Together, Kaileena and the Prince defeat the Dahaka, the enforcer of fate, and journey to Babylon in peace.
The Two Thrones
Kaileena arrives to a Babylon occupied by a mysterious army. These evil forces attack the Prince's ship and capture Kaileena, and when the Prince attempts a rescue, Kaileena is killed by the Vizier, leader of the army. As a magical being, Kaileena's death triggers the creation of the Sands of Time, which the Vizier quickly utilizes to transform himself into a god.
The Vizier does not enjoy his newfound power long, however, as the Prince decidedly puts an end to his plans. The Vizier dead, the Prince watches as the sands coelesce into the form of a woman. Kaileena's spirit survives within the very sands that spewed forth from her dead body, and she gives the Prince one final "thank you" before ascending to another world.