Andrea Bayard

Rock Dean and Dr. Andrea Romar travel up the Amazon River to find out why the plantation workers have left their work in panic, allegedly because of attacks from Curucu, a monster who is said to live up the river where no white man has ever been before... (imdb)

A guy almost hits a unknown girl on a road at night. She is in panic and seems a little crazy. Go to the mansion of his lover, where the couple takes shelter, hidden, until the caretaker denounces.

A letter summons American detective Steve Marshall to Sao Paulo, Brazil, in search of fugitive murderess Louise Dunning. Marshall contacts Louise and learns that she murdered her husband only in self-defense. In the meantime, Marshall is set up as a pawn in a counterfeiting ring (they were the ones who sent him the letter), and unwittingly helps the police capture the criminals. Louise decides to remain in Brazil. (imdb)