Drug dealers, a Mafioso and a murderer are cast in the roles of Caesar, Brutus, Cassius and others in Caesar Must Die, a docu-drama about inmates at a tough Italian prison who take on a Shakespeare tragedy.
The movie, which has its world premiere at the Berlin film festival on Saturday, was shot at the Rebibbia prison on the outskirts of Rome, some of it in the high security wing.
Directed by veteran Italian film makers Vittorio and Paolo Taviani, Cesare Deve Morire might equally be called Shakespeare can set you free as prisoners mentally escape the confines of their cells, at least fleetingly.
And Shakespeare's themes of power, corruption, murder and vengeance in Julius Caesar naturally resonate with performers who are serving sentences ranging from 14 years to life.
They were in their world but at the same time they had lines of Shakespeare which talked about murder and betrayal ... about power and bosses, and we thought may be we can include their realities in the play, Vittorio told reporters in Berlin.
They lived through personal dramas too and we could link this to the dramatic life of Brutus and Mark Antony, for example, and they were able to put themselves in the shoes of the characters of Shakespeare.
Caesar Must Die is one of several movies at this year's Berlin festival which deal with captivity, and judging by warm applause after a press screening, it could prove popular with the critics and judges.
Though billed as a documentary, the film, shot almost entirely in black-and-white, is in fact a drama or a play around a play. Even when prisoners depart from Shakespeare's text there is a script and elements of performance.
Nonetheless, the intensity of the actors, and extensive use of close-up facial shots, communicate the power of the play and bring it alive for modern audiences.
The downside is that when six months of rehearsal and the final show at the prison's theatre are over, the reality of life behind bars sinks quickly back in.
Ever since I discovered art, this cell has truly become a prison, said Cosimo Rega, the inmate who played Cassius, speaking directly into a camera in his cell.
The Taviani brothers, who have been making films together for 50 years and in 1977 won the Palme d'Or at the Cannes film festival for Padre Padrone, first got the idea for the film from a friend who attended a staging at the prison.
She told them that the performance of a staging of Dante's Inferno had reduced her to tears. They too attended a play there and saw the potential for a big screen production.
The movie opens with a series of auditions, during which prisoners lay bare their emotions.
We thought it was important to show the trauma inmates had lived through, said Vittorio. They were feeling pain and ... it should be taken into account.
Most of the cast are still behind bars, although former Rebibbia inmate Salvatore Striano was brought back to the prison to play Brutus and is now an actor.
These men all have to serve their sentences, Striano said. They are all guilty of course, but they kind of asked for pardon through this play, they want to live, inside prison.