One of the most alarming “memory” films of recent years, Chilean director Pablo Larraín’s 2008 “Tony Manero” pondered the activities of a murderous madman living under martial law and obsessively impersonating the protagonist of “Saturday Night Fever.” Larraín’s follow-up, “Post Mortem,” is another dark, deadpan comedy that’s more overtly political and scarcely less disturbing.

“Post Mortem,” which opens in New York at Film Forum today, is set five or six years earlier, in 1973. The first shot, which is something of a postscript, has a tank rumbling over a Santiago street filled with detritus — mopping up after the military coup led by General Augusto Pinochet overthrew Salvador Allende’s socialist government. The inspiration, according to the 35-year-old director, came from the story of the assistant coroner who performed the actual autopsy on the deposed Chilean president. The desire for a postmortem doubtless derives from Larraín's personal history: he was born three years after the coup to a wealthy, politically prominent family closely associated with the rightwing Independent Democratic Union.

Like the novels of the exiled Chilean writer Roberto Bolaño, “Tony Manero” suggested that lawless police states enable all manner of freelance killers. “Post Mortem” makes the same point in somewhat subtler fashion. The protagonist Mario — blank-faced, lank-haired Alfred Castro, who played the madman in “Tony Manero” — is here, as in Larraín’s previous film, understandable only as one who is wholly absorbed in his own particular delusion. In this case, though, Larraín's anti-hero — a gray “functionary” in the Santiago city morgue — becomes involved with an equally self-involved fantasist. She happens to live directly across the street, an over-the-hill dancer at the Bim Bam Bum nightclub who refers to herself in the third person, as Nancy Puelma, and her suitor as “neighbor.”

These two, “an apparently insignificant and charmless couple,” as Larraín calls them, are largely indifferent to the political crisis around them, despite the fact that Nancy, living with her father and brother, is surrounded by leftwing activists. Bringing her home from the Bim Bam Bum (it’s their first date), Mario drives into a massive demonstration in support of the Allende government. Spotting someone she knows, Nancy bails from the car without a word. Here, Larraín flashes forward to the last time the couple will meet — in the morgue — as if to suggest that they are dead already.

Everything in “Post Mortem” appears washed out and enervated. Bored by the p0liticals who are meeting in her house, Nancy goes across the street to Mario’s to initiate one of the most desultory affairs in the history of movies — the mingling of two dust-bunnies. Mario fails to impress Nancy by taking her out for Chinese food (“Why did you bring me here, neighbor?” she wonders). Neither does his plan to give his car to the cabaret boss in order to get Nancy back on stage succeed. History intervenes. Mario emerges from his shower on the morning of the coup to find empty streets, smashed cars, and Nancy’s home trashed.

The morgue is a grotesque, bureaucratic nightmare — overflowing with bodies, some still alive, and occupied by soldiers. Mario himself is “drafted” to document the Allende autopsy that, in one of the movie’s most harrowing scenes, his colleagues are unable to perform. (Reportedly, Larraín shot the sequence in the actual morgue, on the actual table, where Allende’s corpse was examined). When Mario finds Nancy again, he is (in his way) a member of the newly installed fascist regime and she (in hers) is a political fugitive.

In Bolaño’s “Distant Star,” the so-called New Chilean Poetry of the Pinochet dictatorship is announced by the inexplicable murder of an entire household, including the beautiful, literary Garmendia Twins. “Post Mortem” has its own, more inexorable shock ending. Building in intensity, this is a movie that’s both elusive and visceral in its metaphors. The perverse anti-virtuosity of the filmmaking heightens the sense of pervasive shabbiness and ineptitude. It’s a new and original vision of political terror.