O Estranho Vício do Dr. Cornélio (1976)

Cornélio, an aged man and famous baritone, marries the young Angelica, who plans with her ex-boyfriend Bruno, to kill the husband with contaminated oysters, but she ends up the one who gets sick. In the hospital, she demands Bruno's presence and he becomes a Cornelio friend, even though his continued attempts to kill the oldman.