Montserrat has always been overlooked. She's a talented sound editor, but she's left out of the boys' club running the film industry in '90s Mexico City. And she's all-but-invisible to her best friend Tristán, a charming if faded soap opera star, even though she's been in love with him since childhood. Then Tristán discovers his new neighbour is the cult horror director Abel Urueta, and the legendary auteur claims he has a way to change their lives - even if his tales of a Nazi occultist imbuing magic into highly volatile silver nitrate stock sounds like sheer fantasy.