The Edge Of Time

(formerly titled In The Court Of Love And Loss)
Kyrie believes she was abandoned as a 5-year-old child when her people, the Ouri, mysteriously fled the planet Sirene. Proteus returns to rescue the girl who was accidentally left behind, but through a trick of time, he instead finds a grown woman who doesn't realize her own identity or how invaluable she is to Sirene's survival.
And the planet's dictatorial ruler Galen is determined to keep her for himself.