The importance of The Look of Silence — the follow-up to Joshua Oppenheimer’s Oscar-nominated documentary The Act of Killing — can’t be stressed enough. This engrossing piece of cinematic non-fiction focuses on a man whose brother was killed during the Indonesian genocide in the mid-'60s.

This exclusive trailer for The Look of Silence (above) offers a deeper glimpse at the film’s central character who is now trying to track down his brother’s murderers.

Executive produced by doc legends Errol Morris and Werner Herzog, The Look of Silence enters theaters July 17.