On April 20, 2011, only six weeks after attending the Oscar ceremony as a nominee for the documentary Restrepo, photographer and filmmaker Tim Hetherington was killed by mortar fire in the city of Misrata, Libya, where he’d been covering the civil war. In this powerful new feature-length HBO documentary, Tim’s Restrepo co-director and bestselling author Sebastian Junger (“The Perfect Storm,” “War”) traces his close friend’s work across the world's battlefields to reveal what made him such a singular talent — and remarkable human being.