Restrepo, Sebastian Junger's Oscar-nominated 2010 documentary about the war in Afghanistan, dropped us into the thick of battle, into the middle of its strange bedlam, its queasy mix of confusion, chaos, excitement, and fear.

Junger returns us to the same place with Korengal, a remarkable follow-up that switches the focus from the soldiers' experience of fighting to their state of mind after the bloodletting has stopped.

In a series of expertly edited interviews conducted with infantrymen on their way home after a year in the Korengal Valley, Junger exposes us to the war's psychological toll.

The experience is sobering. As multivalent, contradictory, and shocking as the actuality of combat may be, Korengal shows its aftereffects to be even more ambiguous.

The film opens on the face of Spec. Misha Pemble-Belkin, an Oregonian who spent his childhood snowboarding on Mount Hood. He tells Junger he made his time in "death valley," as the Korengal has come to be known, bearable by pretending the mountains around him were those he played by as a kid.

"Whenever I looked out at the mountains, I didn't think 'This is Afghanistan and oh, there's Taliban roaming up there,' " Pemble-Belkin says on-camera. "For the most part, I tried to think back home, somewhere peaceful."

Surely an understandable reaction.

Yet something stunning happens when Junger asks the soldier if there's anything he misses about Korengal.

"Oh yeah, I'd rather be there than here," Pemble-Belkin says. "I'd go back right now if I could."

Other soldiers tell Junger of the gun-lust and bloodlust that takes them over in a firefight - an intense rapture that sharpens their senses and helps them survive. They admit they know little about the geopolitical reasons for the war or what makes the Taliban tick. What matters, they say, is the camaraderie, the brotherly love that impelled them to fight for the guy next to them.

They also talk of the joy and relief they couldn't help but feel when they survived an attack that killed a comrade.

Korengal was created from some of the masses of data, interviews, and video footage that Junger and photographer Tim Hetherington gathered when they were embedded with the Battle Company of the 173d Airborne Brigade from May 2007 to July 2008. (Hetherington died in 2011 while covering the conflict in Libya.)

It's the same material the duo mined for Restrepo and for Junger's best-selling 2010 book, War.

Yet, the film never feels stale or repetitive. As he did in Restrepo, Junger steers clear of politics, remaining stubbornly neutral. This frees him to present the troops' conflicted souls without subjecting the material to too many distracting assumptions and preconceptions.

Korengal *** (out of four stars)

Directed by Sebastian Junger. Distributed by Gold Crest Films.

Running time: 1 hour, 29 mins.

Parent's guide: R (profanity, violence, brief nudity).

Playing at: Ritz at the Bourse.