Aranzazu Berradre Marín has a secret, she’s a cop. And, she’s the only one able to infiltrate the Spanish terrorist group ETA. Not her real name, Marín goes deep undercover, perplexing her enemies and astonishing her fellow officers. Arantxa Echevarría’s nail-biting thriller is based on a true story and won the Goya for Best Film.

Taking place over the course of eight years, Undercover follows Marín as she slowly worms her way into ETA, one of the most brutal terrorist organizations on the planet, who have murdered hundreds of people over the course of years. As Marín faces down sexism in her own ranks, she plumbs the depths of ETA in the hopes of breaking the organization’s back. Undercover is the highest grossing Spanish film directed by a woman.