Chris Smith’s one-man doc on veteran doomsayer Michael C. Ruppert holds less interest as another sky-is-falling dispatch than as the filmmaker’s return to warts-and-all portraiture after 2008’s well-received fiction feature The Pool. Ten years ago, Smith’s rephouse-circuit hit American Movie was taken as a mockumentary of an amateur horror auteur, but it was also an unexpectedly touching look at a decent-hearted striver. Ruppert, an ex-cop whose eye bags betray that he hasn’t slept since a Carter-era dust-up with the CIA, is another subject with overshare vulnerability and a desperately headlong worldview. Ruppert’s apocalyptic, oil-focused monologues, shot in bunker environs and edited to a rising pitch, take familiar Bush-era lefty positions on environmental and economic woes and add a chaser of survivalism. Smith lets Ruppert’s plainspoken autodidactic skepticism get gradually shriller until his arguments dissolve into tears of grief and frustration. There’s an element of Errol Morris in the film, which implicitly psychologizes its subject and watches as he talks himself deeper and deeper into the hole. Smith’s interest in the underdog also lends a reserved sense of sympathy: By faithfully documenting Ruppert’s long-simmering analysis, Smith lets us experience the feeling of a world gone to pot, whether or not the claims are factually accurate. That said, the hastily made film is inferior to American Movie (or Smith’s bleak American Job), and you would not want to be caught next to Ruppert on a transatlantic flight.