In 1995, two actors called Milo Addica and Will Rokos got together to write a screenplay called Monster’s Ball. As the above extract indicates, it takes its title from what happens the night before an execution. But the story isn’t about the death penalty: it’s about how people can escape the prisons they build around them. It’s about struggle and survival, about tolerance and redemption - or, as director Marc Forster puts it, “a cautionary tale about the price of complacency”. It is also a passionate love story between two people who thought love had passed them by.

Monster’s Ball is set in present-day Georgia, and its central character is Hank Grotowski (Billy Bob Thornton). A career prison officer, Hank is a product of his world: a taciturn, hard-drinking, misogynist who blames his wife for dying. His father, Buck (Peter Boyle), now tied to an oxygen tank with emphysema, was a prison officer before him. And his boy Sonny (Heath Ledger) shows every sign of following in his footsteps: already a member of the execution team, he is likewise a study in barely controlled anger and seething emotions.

Then the lid blasts off. Taunted by Hank for breaking down at an execution, Sonny commits suicide in front of his father in the living room, leaving Hank to confront his own failure. Thornton’s peformance barely hints at what is going on behind the coiled-steel facade, but it is clear that something will have to give.

Hank abruptly quits his job at the prison and goes into a kind of suspended animation, driving around late at night, seeking comfort in chocolate ice cream and paid-for sex. Then, one evening, he comes across Leticia (Halle Berry) by the roadside, distraught because her overweight son, Tyrell (Coronji Calhoun), has been hit by a car. He doesn’t know she is the widow of a man he has just helped execute, and she has no idea he was present at her husband’s electrocution. He drives her to the hospital but, when the boy dies, finds himself first clumsily comforting Leticia, then irresistibly drawn towards her, breaking down and talking for the first time about Sonny’s death.

It is the crux of the film - the point at which it becomes the story of an unlikely but supercharged relationship which transforms the two damaged people involved, enabling each to share and go beyond his or her private pain. And it makes it easy to understand why, during the late nineties, Monster’s Ball was one of the most talked-about scripts in Hollywood, attracting actors of the calibre of Robert De Niro and Tommy Lee Jones and directors of the order of Sean Penn and Oliver Stone.

But the budgetary demands that came with that sort of cast brought with it pressure on Rokos and Addica to soften their screenplay, which pulls no punches when it comes to the circumstances of Hank and Leticia’s life. For a while, the two writers thought of scraping together a tiny budget and making the film themselves. But then, in 1999, the project ended up at go-ahead indie Lions Gate with a young Swiss-born film-maker called Marc Forster, whose debut feature, Everything Put Together, had just been in competition at Sundance.

Although the budget was a lot higher than it would have been if Rokos and Addica had made it, there was no call for change or compromise. More impressively still, the film attracted a cast every bit as strong as any that had previously been attached to it. A potentially explosive pairing, Thornton and Berry take no hostages in their playing of two desperate, angry, lonely people who grab their one remaining chance of happiness with a passion neither knew they still possessed. The atmosphere on set, says Forster, was sometimes so intense that he felt like an intruder.

But, to judge by the footage available when Preview talked to him in August, just after he had delivered his first cut to Lions Gate, the experience didn’t daunt him, and he seems certain to deliver a film whose cool style and total control provide a perfect framework for the two supercharged performances at the heart of the story.