This on-the-ground exercise in embedded journalism looks at the real-life journeys of two modern-day vigilante groups as they battle the murderous Mexican drug cartels. In the Mexican state of Michoacán, a small-town doctor leads a citizens uprising against the local drug cartel. In Arizona's Altar Valley, an American veteran heads a small paramilitary group trying to stop Mexico's drug wars from crossing the border. Filmmaker Matthew Heineman snagged two major awards at this year's Sundance Film Festival for this vivid documentary about ordinary people fighting corruption. 98 minutes R.