Dead Man Walking an emotional triumph at the London Coliseum

Dead Man Walking had its origins in a 1993 memoir by Helen Prejean, an American catholic nun, telling of her experiences in comforting inmates on Death Row in a US jail. The book became a New York Times best-seller and was nominated for a Pulitzer prize. It was released as a film in 1995, for which Susan Sarandon won a Best Actress Oscar while Sean Penn and Tim Robbins were nominated for Best Actor and Best Director.

In 2000, the American composer Jake Heggie turned it into an opera which has been seen in many countries as well as the USA, but the current production in London is the first time a fully-staged version has been seen in the UK. To judge by the huge impression made on the audience, the 25-year wait has been worth it, with superb acting and singing, inspired direction by the ENO's Annilese Miskimmon and intriguing music from Heggie all playing their part.

Helen Prejean's original book concentrated on her dealings with two convicted murderers, who had both been sentenced to death. Their stories were condensed into the single role played by Sean Penn, and Terrence McNally's libretto for the opera follows that example.

Watching the film for the first time a day before I saw the opera, I was intrigued by a line from a prison official explaining to Prejean why the convicted murderer was refused his request to have a hymn tune played as he received his lethal injection: "Experience tells us that music stirs up emotion: emotion that can produce an unexpected reaction in the inmate." On hearing that, I wondered what reaction Heggie's music would create to add to the story. Ranging from gospel music to dramatic sounds to accompany the rape and murder depicted at the start of the opera, he manages always to enhance what we are seeing, without letting the orchestral sound become too prominent. The conductor Kerem Hasan plays a large part in ensuring a proper balance between music and acting.

Both the leading roles, Sister Helen Prejean and the prisoner Joseph de Rocher, are perfectly sung and acted by Christine Rice and Michael Mayes respectively, with Mayes particularly showing the commitment that has led to his becoming the top choice for this demanding role. Rice performs impressively throughout, particularly when she conveys the bemusement felt when she meets the parents of de Rocher's victims and begins to appreciate the depth of their feelings too.

The different emotions and viewpoints of the various characters come through powerfully in the libretto, but the most profound moment of Miskimmon's hugely effective direction comes at the end when de Rocher receives his lethal injection. I have never seen such total concentration in a theatre audience and rarely heard from them such complete silence as accompanied Heggie's solemn music. Even the usual mandatory coughing was completely absent.

Dead Man Walking is not something to go to if you want to be entertained, but for an emotional experience that challenges your views on every aspect of humanity and the death sentence, it is unbeatable. This is certainly the most intense and probably the best opera I have ever seen from the ENO.