Joe Penhall on adapting The Road

In the Guardian, Joe Penhall recounts his experience of adapting Cormac McCarthy's The Road, including the time the author came to a special preview screening.

The first thing he said he liked about the film was the voiceover. This had been a source of consternation for some time. Initially, I wanted to write one to fully capture McCarthy's coruscating lilt – but Hillcoat didn't want it. Then, once it was filmed, the producers wanted the voiceover. Hillcoat reluctantly agreed but our star, Viggo Mortensen, was dead against it. Nick Cave, who was scoring the film, was all for it. Meanwhile, Robert Duvall, who is in arguably the best scene in the film, had taken to improvising his own extraordinary dialogue, which some of us thought might make a fine voiceover. When I finally sat down in my Sunset Strip hotel room to finish writing it, with eight worried people on a conference call chewing over every word, the voiceover was beginning to look doomed. Now we had it from the horse's mouth: "It's very successful. It really works." I wanted to lift McCarthy off his feet and give him a bear hug.

The Road opens in the UK on 8th January.