Star who keeps changing tracks

Philip Seymour Hoffman is best known on this side of the Atlantic as a movie actor, where roles in films such as Todd Solondz's Happiness, Paul Thomas Anderson's Boogie Nights and Magnolia, and Cameron Crowe's Almost Famous have marked him out as a serious talent.

But across the Pond he's also a name to be reckoned with in the theatre, both on stage and behind the scenes. And it's his work as a director that brings him to London this week, staging his acclaimed off-Broadway production of Stephen Adly Guirgus 's Jesus Hopped The 'A' Train at the Donmar Warehouse.

Set in New York's Ryker's prison, 'A' Train explores the psychology of two prisoners kept in solitary confinement. One is a serial killer turned born-again Christian, the other a convicted murderer appealing his sentence on the grounds that he had good reason to kill.

'It's about two men battling about God and God's will,' explains Hoffman. 'It's about accepting responsibility for what you've done and becoming a man - it's big, big stuff.'

Hoffman is the co-artistic director of New York's LABrynth Theatre Company and works closely with Guirgus to develop pieces inspired and energised by the city.

'Stephen will approach me with ideas before he starts writing,' explains Hoffman. 'Once he's begun to put it down on paper, we take it into rehearsal and we just keep working on it. We only take ideas into rehearsal that we believe will eventually be thrilling and though ultimately it's Stephen's play - he is the writer - it may take a year-and-a-half from that point to evolve.'

Evolving is something Hoffman is big on and the reason he found himself directing: 'The more I acted, the more I found myself spending time at rehearsals thinking how the play should be told and becoming interested in the play as a whole,' he recalls.

He feels that his understanding of the acting process really bears fruit when he directs. 'I discovered I had a facility to help them be the best they could be,' he says.

Nevertheless, he admits that occasionally it does require some self-restraint. 'Sometimes you do get frustrated and you want to go: 'Oh, just do it like this'. But you have to remember that as an actor you're subjective and it's hard to have the objectivity a director has. It takes time for that objectivity to sink into the actor's gut, so you've got to be patient and know that it will come.'

He is pleased to be bringing the original cast of 'A' Train to London (a slightly different one to that which played Edinburgh last year), excited to witness the collision of cities and cultures. 'For the most part, the roles were written for the actors who play them,' he explains. 'Both the writer and the actors are coming from what they know; it's the way they speak the language, the rhythm, the passion. I don't think a play can be more representative of New York City than this one.'