Caesar Must Die picks up where Shakespeare’s The Tragedy of Julius Caesar ends, as heavy-hearted Marcus Brutus, one of Caesar’s assassins, impales himself on a sword. Antony pays tribute to the “noblest Roman of them all”. And the lights go up on an all-male cast.

This, we immediately realise, is no ordinary touring production but a theatrical experiment in Rome’s maximum security Rebibbia Prison. The Shakespearean players are drawn from real-life murderers and Mafiosi. Their sentences flash up on screen and seem to add up to a geological age.

The octogenarian Taviani brothers won Berlin’s Golden Bear with this hybrid drama fashioned around the prisoners’ staging of Julius Caesar. Hearkening back to the bastardised documentary of the Tavianis’ 1977 Palme D’or winner Padre Padrone, Caesar Must Die is an unusual marriage of script, restaging and chronicle cooked up between the brothers, their cast and Rebibbia theatre director Fabio Cavalli.

Rehearsal scenes rendered in black and white quickly find echoes in the politics and personalities of the prison yard. Colour scenes taken from the production further articulate the parallels. The process, as documented and recreated for the camera, builds into a tremendous production of Julius Caesar. The ensemble, one feels, is acting for their very lives.

The juxtaposition of Shakespearean text and prison cell life is a particularly poignant one. The inmates master the Bard, only to return to their individual sentences. “Since I got to know art, this cell has become a prison,” mourns life-prisoner and the production’s Cassius, Cosimo Rega.

Julius Caesar adds to an already meta-textual effect. At certain points we’re watching inmates rehearsing at being inmates rehearsing as they work through a play that’s defined by rehearsing. They are, moreover, murderers playing murderers, a remove that allows them to ruminate meaningfully on their past, on relationships, and on betrayal.

Never mind the brief run time: those 76 minutes are eventful, loaded and most worthwhile.