The story follows Irena Gallier (Nastassja Kinski), a young woman who reunites with her brother Paul (Malcolm McDowell) in New Orleans. Unbeknownst to her, they descend from a race of shapeshifters who transform into panthers when sexually aroused. The transformation can only be reversed by killing a human.

As Irena begins a romance with zookeeper Oliver Yates (John Heard), her sexual awakening triggers the dormant curse. Her struggle with desire, identity, and inherited fate intensifies as her brother Paul urges her to embrace their monstrous lineage.