In a secret, dimly lit chapel, Lily Lane, the demure nun, confesses her forbidden desires to Father Stirling Cooper. Her stepmother, Petra Blair, a sultry vixen in a latex habit, listens, her eyes gleaming with shared lust. Stirling, bound by his vows, suggests a game of role-play, a safe outlet for their taboo fantasies. Petra, eager, commands Lily to her knees, binding her wrists with silken cords. Lily, now the submissive, feels a whiplash of anticipation as Stirling, now the stern master, takes up the crop. Their moans echo, a symphony of sin, as they indulge in their bondage fantasy, a twisted trinity of pleasure and penance.