Bill Viola is renowned the world over as a pioneer of video art. As the Royal Academy in London mounts a major exhibition of his vast and immersive installations, alongside works by Michelangelo, imagine... charts Viola's career over 12 years and follows him as he creates his most high-profile commission to date, Mary and Martyrs, a permanent installation for St Paul's Cathedral. Gerry Fox's film follows Viola on set as he films, with stunt gear and pyrotechnics, his striking visual tableaux in fields, salt lakes and studios. Viola talks candidly about his preoccupations with life, death and suffering, alongside his wife and collaborator Kira Perov.