Prisión Ámbar is a 2009 Mexican drama directed by Octavio Gasca in which Laura, a young violinist trapped in a rocky relationship with Toño, her unemployed and frustrated writer boyfriend, finds herself in an increasingly dangerous situation when Hernán, a stagehand who stumbles upon Toño's intimate love letters to her, becomes completely obsessed and begins stalking her — creating a suffocating triangle where her failing relationship and Hernán's growing fixation threaten to consume her entirely.