Dir:

David Mackenzie

With: Jack O'Connell, Ben Mendelsohn, Rupert Friend

Runtime: 106 minutes

THE first thing to say about David Mackenzie's outstanding prison drama is that it is not Porridge. Norman Stanley Fletcher, Mr MacKay, and their Ealingesque sparring are a picnic in the park compared to Starred Up's dish of gulag gruel seasoned with razorblades. The only humour here is of the gallows kind, the only light that which comes through the barred windows, but the Scots director and his cast still manage to deliver a picture that shines with humanity.

All of which will be a pleasant surprise to those who were hardly enamoured of Mackenzie's last picture, Perfect Sense. Someone not too far from here may have renamed this deeply drippy science fiction cum romantic drama about a mystery virus that renders victims senseless "Perfect Mince". Starred Up shows, however, that there need be no end of acts in a director's career, and Mackenzie shows here what a potent filmmaker he can be when he plays matters straight down the line.

The title refers to the practice of transferring a violent young offender to an adult jail before the age of 21. Eric (Jack O'Connell, Skins) is the 19-year-old inmate in question and the first sight of him shows that he is well acquainted with the justice system. This new home appears to be a case of same doghouse, different kennel.

Except this time there are some differences. For a start, this prison runs group therapy sessions. Led by Oliver (Homeland's Rupert Friend), who reckons he feels at home in prison because he went to boarding school, the sessions try to cut down on prisoner on prisoner violence by encouraging inmates to talk to each other. The prison officers would rather not touch this touchy-feely lark with a bargepole, and barely disguise their contempt.

Besides the therapy sessions, the jail has another USP: Eric's estranged dad is in the same place. Eric and Nev (Ben Mendelsohn, excellent in the Australian crime drama Animal Kingdon, terrific here) offer walking, talking, snarling proof of Larkin's warning about man handing on misery to man.

From minutes in, as Eric establishes himself as a force to be reckoned with, Mackenzie keeps the tension high and mounting. Working from a screenplay by Jonathan Asser, who was a prison psychotherapist, he looks at the relationship among the three characters at the same time as keeping the focus tight on Eric. Behind these three, it becomes clear, are other networks, different connections. The jail is a melting pot of misery, a pan ready to boil over, and all one can do is watch, horrified yet enthralled, while it does. We may not warm to all of these characters, some of their actions fair turn the stomach, and the violence is similarly gut wrenching, but there is no fleeing the prison Mackenzie has built, nor would one want to.

Prison works for movies. From Cool Hand Luke and Birdman of Alcatraz to The Shawshank Redemption and A Prophet, the best are stories of essentially good men (or so we want to think) in bad places, individuals being chewed up by the system, but who refuse to be spat out and left for dead. The finest are also those that do not pull their punches. Although The Shawshank Redemption frequently hits the top spot in lists of beloved movies, it is hardly an easy watch. We witness the rebirth of Andy Dufresne's spirit, but not before seeing it come close to dying.

Starred Up, being a British prison drama, and a relatively low budget one at that, is more at home at the Scum end of the spectrum than the Shawshank. There are scenes here that will stay with you long after the last cell door has clanged shut. The general atmosphere - the music blaring, the shouting, the sense that violence is only ever a second away - shreds the nerves from the off.

His stage set for triumph, tragedy, or another outcome, Mackenzie lets the drama play out. He is spoiled for choice as to which juicy conflict he will explore, be it son versus father or the liberal therapist against the conservative establishment. The former is the stronger and more novel, and after a time Mackenzie rightly settles on it.

Mendelsohn and O'Connell go at the their parts as if parole from life sentences depended on it. Both can pelt from nought to 90 when occasion demands, but it is in the quieter, more restrained moments that they show true acting class. Nev's attempts to simply talk to his son, to make a connection, are heartbreaking in their own way. Few words are used, but volumes are spoken.

As accomplished as the other performances are, it is O'Connell who is the star attraction of Starred Up. He takes the almost cliched character of an angry young yob and mines surprising depths from him. This is a character who will not be taken for granted in a film that revels in keeping the audience on edge.

The perfect prison movie, indeed.