In honor of Cinco de Mayo (which, lest we forget, is not just about margaritas), we highly recommend you take some time out from your day to watch an extended preview for the arresting documentary El General. Filmmaker Natalia Almada’s conflicted look at her controversial great-grandfather, General Plutarco Elías Calles, uses archival footage and audio recordings of Alamada’s grandmother to paint the portrait of the man who rose to become Mexico’s president. The clip comes to us courtesy of our friends at video magazine Telegraph 21, who are currently sponsoring a very exciting student documentary contest.