In the imaginative and affecting documentary “Theo Who Lived,” the writer and journalist Theo Padnos walks the viewer through his nearly two years of captivity in the hands of Al Qaeda. A self-described “dumb American,” Mr. Padnos, who went by the name Peter Theo Curtis at the time, crossed the border into Syria from Turkey in October 2012, looking for a story. He was kidnapped almost immediately.

The writer and director David Schisgall follows Mr. Padnos around his old quarters in Turkey, and recreates the basement rooms and cells in Syria in which Mr. Padnos was held, at one point in near-solitary confinement for over 200 days. Mr. Padnos’s mother, Nancy Curtis, recounts tales from her Vermont home, including the story of her friendship with the family of James Foley, another kidnapped American journalist whose appalling execution video made headlines in 2014.

Mr. Padnos is, among other things, a compelling movie character: voluble, articulate, energetic and still understandably agitated. As indignant as he is when he describes his brutal treatment (beatings and torture were frequent, as was extreme isolation), he also frequently speaks of his understanding of his captors’ virulent anti-Americanism. He remains angry with a onetime cellmate, the photojournalist Matthew Schrier. Mr. Padnos says he helped Mr. Schrier escape. This seems to be the only thing these men agree on. The still-glowing resentment Mr. Padnos has for Mr. Schrier makes for a surprising and gripping scene. How Mr. Padnos made it out alive also provides a jolt, while the revelation that Mr. Padnos now spends much of his time assisting and comforting Syrian refugees is very moving. This is a potent, vital film.