The future has been old hat since Fritz Lang’s “Metropolis” emerged 80 years ago. The film’s iconic images — gray, trudging masses of workers, streamlined cityscapes with skyscrapers and zippy overpasses, a diabolical and deadly android — catalogue the classic dystopian vision of industrialized man with a monumental finality. The silent masterpiece returns today to Film Forum for a weeklong run to mark its 80th anniversary, and it still packs a heavyweight punch.

A mega-production with equivalent hype, “Metropolis” was erected under the merciless direction of Lang (1890–1976), who was at his peak while still in Germany (he fled for Paris, and eventually America, in 1933). Under the aegis of the famed UFA studios, Lang worked his young stars and proverbial cast of thousands to the bone, amid intricate Deco-tastic sets ingeniously rigged with miniatures and mirrors for special effects. Part of an effort to make inroads in the American market, the architectonic project amounted to an attempt to “out-big” Hollywood, powered by German Expressionist expertise and the conceptual ferment of European contemporary art.

Sliced and diced after its Berlin premiere, and again for export, the original 2 1/2-hour version acquired, like a lost Atlantis, its own mystique. Film Forum is showing a new print of the 2002 restoration, a landmark of reconstruction and beautification first screened there five years ago. No one begrudges the camp value of Giorgio Moroder’s 1984 re-jiggering of the film, nor the merits of Kino’s DVD edition. But this week, Film Forum is your gateway to “Metropolis,” the better to kneel in awe before mighty temples to progress and doom along with the rest of the peons on-screen.

Those peons, the worker class of “Metropolis,” don’t hit the big city much, because they live, work, and die beneath its crushing mass. Echoing H.G. Wells’s “The Time Machine,” this fantastic literalization of “upper” and “lower” classes situates the rich above ground, while the poor file in pharaonic shifts to infernal underground factories. While the youthful scions of industry magnates flex and cavort with nymphs in a paradisiacal garden called the Club of the Sons, the ageless subterranean mole-men contort and twitch their limbs at clockwork controls as if in grotesque perversions of Da Vinci’s “Vitruvian Man.”

The story, by Lang’s tireless scenarist, one-time wife, and eventual Nazi, Thea von Harbou, begins with jodhpur-wearing Freder Fredersen (Gustav Fröhlich), the son of the city’s mastermind. Smitten with Maria (Brigitte Helm), a sinewy blond agitator from the lower depths, he is possessed by empathy for the workers and swaps identities with one (#11811, to be exact). But the prospect of boy-meets-girl is swiftly annihilated by mad-scientist-makes-robot-version-of-girl — a scheme hatched by Freder’s father to infiltrate and quash a secret proletarian mutiny.

Amid all the film’s class binaries, and the frenzy of real and fake idols, the archaic inventor of the fake Maria is an intriguing hermeneutic holdout. Beethoven-maned Rotwang (Rudolf Klein-Rogge) inhabits a warped cottage in the urban jungle, like a church in Midtown Manhattan. Redolent of Black Forest magic and flaunting pentangles, he’s a bit of folk and magic right at the heart of Lang’s parable of progress. One of the film’s extant gaps in footage, which the restoration details with inter-titles, even develops Rotwang’s cryptically suggestive link with the elder Fredersen as competing suitors for Freder ‘s mother.

A demonic strain emerges in the fake Maria’s totemic poses. Her glyphic dances mesmerize the panting, partygoers of Metropolis’s limelight district, Yoshiwara; below, her gesture-laden speeches rouse the rabble to their self-destruction. Lang, ever the orchestrator, lets “Metropolis” rise to a similarly feverish pitch, staging a biblical flood and a life-and-death struggle at great heights. On a larger scale than his German pulp thrillers (1928’s “Spies”) and American noirs (1945’s “Scarlet Street”), he created a conspiratorial reality that coils and constricts on its human agents.

After all the sturm und drang, “Metropolis” concludes, sentimentally, with reconciliation, dramatizing its only-in-a-silent-film opening title: “The mediator between heart and hands must be the heart.” (The cornball conclusion, too, as anyone trolling Lang’s back catalogue can attest, would remain a habit of this strange determinist.) It was an ending that pleased neither right nor left, which may be why the epic-length movie failed to click with audiences.

A few years on, the prolific Lang would direct another indelible masterpiece, the pioneering sound film “M,” scoring, with “Metropolis,” “Spies,” and 1924’s “Die Nibelungen,” one of the most fertile and influential stretches in film history. “Metropolis” stands tall as a must-see monument of silent cinema and world history. Leave it to Lang to unleash his opus in the same year as Walter Ruttmann’s lyrical ode to urban life, “Berlin: Symphony of a Great City.”

Through July26 (209 W. Houston St., between Sixth Avenue and Varick Street, 212-727-8110).