Poor orphan girl Therese (Alice Arno) has a difficult life and winds up facing public execution. Miraculously she is rescued at the last minute by a wealthy couple who intervene to stop the execution. But the couple take an overly great interest in her background and introduce her to a world of sexual depravity and submissiveness. She escapes but Therese (or 'Justine' as she is known to her various sexual captors) just keeps ending up in darker and darker adventures. She heads for sanctuary in a monastery but soon finds herself the plaything for a local nobleman. But will all this degradation lead her to greater self-awareness... or death?