Filho is a weak-willed old man in love/lust with his girlfriend Formosa; there is little to indicate she feels the same way. Their couplings are brief and not particularly romantic. She threatens to move away without him unless he gives up his elderly mother, a religious fanatic, for her. He can't do it and breaks down after discovering her whoring herself. Not only that but Formosa turns out to be a devil worshiper. Possessed, she compels Filho to show his devotion to her by returning with his mother's heart. What follows is a sad, sickening spectacle that shows both religion's tendency to be judgmental and the selfish, evil nature of devil worship.