In the early 2000s, the Earth Liberation Front was making news by setting fire to various targets, including a Hummer dealership; a logging company; and an expansive, new dining hall at the Vail ski area. The first-rate If a Tree Falls, focusing on the sad story of Daniel McGowan who committed acts of arson for the Front, takes an incisive look at this shadowy group in the aftermath of a series of arrests and plea bargains. Director Marshall Curry came across the story serendipitously when a member of the Front, as well as a work colleague of Curry’s wife’s—was arrested without warning at the office. The film follows through the legal process. Comprised of activists who have good intentions but who also seem confused, cops who mean well (and some who don’t), and a snitch who seems nothing but low-down, this intense, and at times graphic, film will stay with you. It is at once a compelling and cautionary tale that smartly delves into the complexity of extreme action.