Writing of 1939’s James Cagney-George Raft big-house melodrama “Each Dawn I Die,” late film historian David Shipman said, “The title presumably referred to prison life, and suggested gloom and tragedy. But the way they played it, it was rather a thrill a second.”

There’s something of a similar disconnect to “A Twelve-Year Night,” Uruguay’s Oscar submission feature. Though decidedly non-pulp, this fact-based tale of three political agitators’ long solitary confinement under military dictatorship is given such bravura cinematic treatment that exciting technique almost overwhelms communicating the titular experience of grueling, punitive isolation. Nonetheless, it’s an impressive work that further confirms writer-director Alvaro Brechner as one of the leading South American screen talents to emerge in the last decade.

Seen as an active threat to recently installed military rule, particularly after it moved from nonviolent protest to kidnappings and assassinations, the Tupamaros Revolutionary Movement (or MLN-T) was vigorously snuffed out by government forces in 1972. The focus here is on three leaders who were removed from prison the following annum, spending the next dozen years as army hostages moved in secret from one subterranean site to another. (Nine MLN-T members were dealt with thus, in total.) The point was to keep their whereabouts and survival status unknown, helping suppress popular opposition. But their individual treatment was also designed to break the prisoners’ health and will, even to the point of madness.

That last aim didn’t work out, in the long run: Finally freed in 1985, once liberal democracy returned to Uruguay, the men depicted became major national political and cultural figures. Mauricio Rosencof (played here by Chino Darin) solidified his early promise as an important author. Eleuterio Fernandez Huidobro (Alfonso Tort) was the nation’s minister of defense when he died two years ago. Carrying his unaltered social justice ideals to the highest office, Jose “Pepe” Mujica (Antonio de la Torre) served as Uruguay’s 40th president from 2010 to 2015.

We don’t glimpse that future (beyond brief written postscripts), or see much of the protagonists’ pre-incarceration lives, beyond a few memory flashbacks often commingled with dream content. (An exception is one long, suspenseful sequence in which military police spare no firepower raiding a suburban home where several MLN-T members are hiding.)

As a result, there’s not a lot of character distinction between our heroes — whom we view for most of the two hours here in separated but identical circumstances, and who seldom speak — despite the personalities of the international actors cast. They’re frequently blindfolded and when not, usually have nothing to look at but blank walls in the bleak environs (cells, empty grain silos, etc.) they’re housed in.

Inspired by a memoir penned by Rosencof and Huidobro, “Night” naturally gravitates to the few distractions these men found from a confinement of tedious deprivation, in which they were denied not just books and human contact but often any daylight.

Still, one could argue that Brechner overcompensates in this direction to a counterproductive degree. His prior features “Bad Day to Go Fishing” (2009) and “Mr. Kaplan” (2014) were both unusually complex comedies, stylistically and tonally. Humor wouldn’t seem to have much berth in this story, yet he finds numerous ways to shoehorn it in, most notably in a set-piece demonstrating the absurd bureaucratic hurdles jumped simply to allow a handcuffed prisoner’s bum to reach the toilet seat. There’s also wit in the protagonists’ figuring out how to communicate with one another via wall-tapping, as well as Rosencof’s playing Cyrano for a guard without the vocabulary to woo his lady friend via love letters.

But there are so many such “exceptions,” they almost come to seem the rule. Twelve years also appear to dash by when we constantly see the heroes being carted from one clandestine locale to another; how can they be bored when it feels like they’re always on the move?

On top of all this, Brechner further enlivens “Night” with an array of elaborate visual and editorial gambits that are often striking in themselves, but taken as a whole tend to work against the general theme. (Even torture is reduced to one high-energy montage.) He may think he’s made a film about existential doubt and threadbare survival, as signaled by the opening Kafka quote. But moment by moment, the movie is so resourcefully busy it nearly makes prolonged, extreme deprivation seem like an invigorating odyssey of self-actualization. The result is a movie that packages soul-grinding monotony for the short-attention-spanned viewer.

Nonetheless, it’s impossible not to be moved by the characters’ climactic return to society, or to be engaged by the craft and performance commitment on display here. If Brechner was possibly the wrong artist for this particular job, the passion he brings to it is still admirable, even when somewhat off-point.

Every element in the tech/design package is first-rate, starting with Carlos Catalan’s cinematography. Alternately poetical, rigidly formal, athletic and head-on brutal, his images are superb yet — like so much here — run a gamut that is almost too dynamic for a movie about the human body and spirit nearly starved of all sustenance.