Here’s how gripping the documentary “Detainee 001” is — a CIA officer saying, “Uh, we f—ed up” amid an uprising at Afghanistan’s Qala-i-Jangi prison barely makes the list of most bonkers moments in this narrative of the early days of the post-9/11 world.

Not many documentaries feature spies working in the field, or offering candid and profane assessments of missteps. Greg Barker’s new film for Showtime has a surplus of vivid footage. Battlefield behavior can be rough; Barker doesn’t look away.

That includes an extensive interview from Dec. 1, 2001, with John Walker Lindh, the so-called American Taliban who was the war on terror’s first enemy combatant detainee. Then 20 years old, the California jihadi had just survived days of fighting among the Northern Alliance, Taliban and al-Qaida at Qala-i-Jangi — malnourished, unwashed, a bullet in his leg. 

Conducted by Robert Pelton, a legendary daredevil reporter freelancing for CNN, it’s among the last public interviews of Lindh, who was sent back to the United States, tried and convicted for his association with the Taliban. Lindh was released from prison in 2019.

Lindh told Pelton about the circumstances of his surrender. 

“They had bombed us with airplanes. They had shot missiles. They had thrown grenades. They had shot us with all types of guns, poured gas on us and burned us. They had done everything you can imagine. So the last day … they poured water in the basement. They wanted to fill it up with water. … I think the vast majority of us had drowned, so that morning — and we were standing in the water, the freezing water in the basement for maybe 20 hours. And so after the water had receded somewhat … we began to discuss with one another — just the topic was on our minds, naturally, you know the basement was filled with the stench of bodies, and we didn’t have any more weapons,” Lindh told Pelton.

Thanks to a combination of Pelton, a group of German journalists and even grainy footage from Northern Alliance fighters, there is footage from the battle itself, bodies strewn about.

“The film is about John Walker Lindh on one level; it’s also about this battle, which was massive news at the time,” Barker said on a recent episode of the Political Theater Podcast. “So far, the war had been relatively easy, 100 forces on the ground, CIA guys, air support. And suddenly there’s this close, brutal battle that follows a prison uprising.”

Adding to the poignancy is footage of CIA officers interrogating Lindh. One of the interrogators is Officer Mike Spann, the first American casualty in what would become a 20-year commitment of blood and treasure in Afghanistan. It’s among the last moments in Spann’s life. 

“As a documentary filmmaker, it’s the best footage I’ve ever come across,” Barker said. “The film is kind of an immersion.”

Barker has spent years chronicling the fallout from 9/11. He was on the ground in Afghanistan shortly after the U.S. invasion, and a PBS Frontline episode he co-directed, “Campaign Against Terror,” aired before the first anniversary of the 9/11 attacks.

Barker co-directed another PBS Frontline episode, “The Long Road to War,” that aired on March 17, 2003, just days before U.S. forces invaded Iraq.

In 2009 came “Sergio,” a documentary about the late U.N. High Commissioner for Human Rights Sergio Vieira de Mello, who was among those killed in 2003 when the U.N.’s headquarters in Baghdad was attacked. Barker later turned that story into a feature film of the same name for Netflix.

Two years after U.S. forces killed Osama bin Laden in Pakistan, Barker was out with “Manhunt: The Inside Story of the Hunt for Bin Laden.”

“Homegrown: The Counter-Terror Dilemma,” about domestic Islamic terrorism, followed in 2016. The next year, “Legion of Brothers” combined war footage with years-later interviews of Green Berets deployed in the early days of the war on terror. Last year, “The Longest War” catalogued the human cost of the Afghanistan War.

Many of his projects that are not about the war on terror per se complement that narrative. 

“The Final Year,” from 2017, follows President Barack Obama’s national security team as it wraps up his second term, accompanying Secretary of State John F. Kerry, U.S. Ambassador to the United Nations Samantha Power and Deputy National Security Adviser Ben Rhodes. “We are the Giant,” from 2014, is about people caught up in the Arab Spring in the Middle East and northern Africa. 

The timing of “Detainee 001” comes as the world commemorated the 20th anniversary of 9/11 and the last U.S. troops left Afghanistan, and offers a stopping point to reflect.

“Through this one particular story, and then the vilification that happens to John as he comes back to the States, the way he’s treated, or mistreated, by the judicial system, it takes us back to this time that defined … the way we treated people caught up in the war on terror ever since,” Barker said. “You can learn a lot about the war on terror and where we are as a country by looking at how it all began.”