Anyone who doubts that Shakespeare was not of an age but for all time, ages hence in states unborn and accents yet unknown, will rethink after Caesar Must Die/Cesare deve morire. Octogenarian brothers Paolo and Vittorio Taviani’s film is a spot-on casting of the Bard into yet another of his infinite variety of aspects, and its uniqueness and roughness cannot fail to speak to, and win, new generations.

But the seventy-six minutes is more than a mixed Italian dialect (subtitled in English) Julius Caesar reflection on pride, politics, ambition, naïveté and crowd manipulation. The mise-en-scène and the actors intertwine with and reinforce the play-within-a-movie, so that this is not a behind-the-scenes making-of. Nor is it cuddly take on the redemptive powers of teamwork and of art, for several lines, including the final one, underscore that, having flown high in their stage rôles and shouted “Freedom!” en masse, the performers more than ever realize their imprisonment in their fates and double-doored cells.

For that venue for excerpts from the 1599 Globe tragedy is a theater within the High Security Block of Rome’s Rebibbia Penitentiary, where the audience from outside is subject to security checks before entering (and leaving) through metal roller-doors. Rising to his feet from the dead, the noblest Roman of them all (Salvatore “Zazà” Striano’s Brutus) joins hands with fellow actors for curtain calls to celebrate their success as the crowd rises to its, “Bravissimo!”

The public leaves. The cast cannot: guards escort them back to confinement, for they are thieves, murderers, drug traffickers, mob soldiers, these men who have breathed stage but real life into their forbears of 44 bc. The twenty selected, long-termers and lifers, state personal data, crimes and sentences, as they audition -- two improvs, one sad, one angry -- before Fabio Cavalli, author, screenplay collaborator with the Tavianis, and director of legitimate theater as well as of three companies of inmate-actors.

Fore and aft, their staged Caesar is in bleached reds and blues, but all else is DP Simone Zampagni’s beautiful unshadowed black and white, in emphasis of the real-life situation-location and of a present look back to a past that in its human essentials does not differ from the now.

With a spare percussive score co-composed by Vittorio’s son Giuliano, and fickle plebs noise from barred windows, the neither fully documentary nor fiction is free to concentrate on its all-white male interactions (only Calpurnia and Portia needed to be cut, and the Nigerian inmate does not audition). Striano had been pardoned in 2006 and, spurred by Cavalli, gone on to a stage and film career. He returned to his former place of incarceration for the four-week shoot; Cavalli “acts” the part of the play director, while the rest are actual current convicts. With his youth and harmonica, Striano’s “cellmate” Vincenzo Gallo, was chosen to play Lucius with his lute.

As with the “director” and among themselves they read the play and become the characters they represent, some make suggestions, such as Francesco Carusone’s that his Soothsayer be “a bit loopy,” while others bare personal antagonisms that threaten to wreck the whole, as between Giovanni Arcuri and Juan Dario Bonetti (Caesar and Decius).

Introducing a little profanity, they test their parts against one another in cells and hallways. Some find it momentarily impossible to continue, when lines remind them of criminal friends they betrayed not in a play but in real life. There is mocking humor -- “I’ve been here twenty years, and you tell me not to waste time” -- and pathos when one reflects that possibly a woman will soon occupy the theater seat where his hand now is.

As much in the corridors, cells and courtyards as on the virtually prop-less stage, these nearly entirely non-professionals give moving performances. Both as Elizabethan Shakespeare’s human ancient Romans and as today’s human convicts, they are authentic, in dual stories which complement and strengthen one other.

(Released by Adopt Films; not rated by MPAA.)