Gullu, a married woman living in poverty, refuses to extinguish her dreams despite the cruelty and violence of her husband. She convinces him to allow her to work outside the home and takes on a job working for psychologist Gul Hanm. The two women form a true friendship, and Gullu sees for the first time that a woman can choose her own life, even while living in a place where man's word and man's fist are the law. But, after a long and unexplained absence, Gul Hanm's estranged husband returns. He wants something she can't give him, and he won't give her something she desperately needs - her freedom.

Once Upon a Time is a story of interweaving lives, bound by threads of deception, the desire for control, and hope in the face of powerlessness.