Saverio, el cruel (1977)

Saverio is an insurance broker who arrives in a small town after receiving a letter from a potential client requesting insurance for "special affections." Upon arriving at the mansion, Saverio is captivated by the beauty of Susana, the granddaughter and heiress to a vast fortune—beautiful, refined, and cultured. What Saverio doesn't suspect is that he will become the victim of a macabre plot, in which he plays a crucial role. Susana, in collusion with her family and friends, will feign madness with the sole purpose of making Saverio fall at her feet.