It explores the year that Junger and Hetherington spent, on assignment for Vanity Fair,[4] in Afghanistan's Korengal Valley, embedded with the Second Platoon, B Company, 2nd Battalion, 503rd Infantry Regiment, 173rd Airborne Brigade Combat Team of the U.S. Army.

As an example of the ever-present dangers faced by the soldiers in the area, the first scene in the film that takes place in Afghanistan depicts a fire-fight after a military Hummer is disabled on a narrow mountain road by an IED.

The remainder of the film chronicles the lives of the men of Second Platoon from a few months after their arrival in the Korengal Valley to the time of their return home.

At Restrepo, the men came under fire almost daily, and often multiple times in a single day, from shifting enemy positions in the surrounding landscape.

During the dangerous mission to hunt Taliban fighters in the Korengal Valley, Battle Company lost Staff Sergeant Larry Rougle[7] during an ambush by a large number of enemies.

A recipient of the Purple Heart who served two tours in Iraq and three in Afghanistan, SSG Rougle was subsequently buried in Arlington National Cemetery.

Interspersed throughout the film are excerpts from interviews recorded with some of the soldiers after Second Platoon returned to the 173rd Airborne Brigade Combat Team's base near Vicenza, Italy, in which the men candidly reflect on their experiences, feelings about those who were wounded or killed, and the emotional distress they will carry with them.

For his actions during Operation Rock Avalanche, Staff Sergeant Salvatore Giunta from 2nd Battalion, who is not featured in the film, would later become the first living person to receive the Medal of Honor since the Vietnam War.