Astounding archival footage, remarkable access and solid source material (the biography Chasing the Flame by Samantha Power) can't hurt a nonfiction filmmaker, but director Greg Barker is also blessed with an inspiring subject in Sergio, his life-and-death story about dashing, high-minded U.N. envoy Sergio Vieira de Mello, whose career was about nothing if not life and death.

Brazilian Vieira de Mello, who had spent his career as a U.N. high commissioner virtually parachuting into global hot spots, had movie star looks and the soul of saint: He was the first U.N. envoy to negotiate with Cambodia's Khmer Rouge, served in Bosnia and Croatia during their dark days and helped East Timor establish itself as an independent democracy. Persuaded by Kofi Anaan, Condoleezza Rice, and Tony Blair, Sergio reluctantly took up his post as U.N. ambassador to Iraq. When terrorists bombed the Baghdad U.N. headquarters on Aug. 9, 2003, Vieira de Mello was trapped in the rubble. For the first time, the U.N. had become the target of terrorism. Using footage of the bomb site and even a feed from a press conference that was going on when the bomb explodes, Barker creates riveting cinema. Winner, U.S. Documentary Editing Award, 2009 Sundance Film Festival.