An Unknown Enemy (Spanish: Un Extraño Enemigo) is a 2018 television historical political thriller and propaganda drama series released on Amazon Prime.

It examines the events leading to the 1968 student massacre and its cover-up, through the eyes of Commander Fernando Barrientos, head of a secret Intelligence agency.

The series main character is loosely based on the real life Fernando Gutiérrez Barrios, director of the infamous DFS intelligence Agency, and depicts the political intrigues that triggered the period of censorship and repression of students at the end of the 1960s.

Season one, comprising eight episodes, aired on Amazon Prime exclusively. It premiered on October 2, 2018, commemorating 50 years of the depicted events. On November 9, 2018, it was announced that the series would be renewed for a second season which premiered on September 28, 2022.