Someone's at the door (1970)

García Bogliano’s love triangle drama follows the unexpected reunion between former high school classmates Alicia and Marianela, whose initially warm meeting takes a sinister turn. Alicia, portrayed by Alexis Cárdenas, becomes deeply suspicious of Marianela, played by Samantha Coronel, as she senses an affair between her husband (Mauro Sánchez Navarro) and her mentally perturbed friend.