When world-renowned American video artist Bill Viola was commissioned to make a pair of permanent installations for St Paul's Cathedral, it was the start of a twelve year journey for the artist and his long-standing collaborator, wife Kira Perov. Director Gerry Fox began filming as Viola's ideas for the altarpieces were taking shape, and continued following progress over years of development and production until, in 2016, the second piece, Mary, was installed alongside 2014's Martyrs (Earth, Air, Fire, Water). Over the course of more than a decade, Fox intimately captures the detail of Viola's creative process and the collaborative relationship between the husband and wife team, whilst also presenting a survey of Viola's major works, reflecting on recurring themes of life, death, consciousness and transition. From the practical considerations of staging epic shoots to the keen spirituality that informs so much of Viola's work, Bill Viola: The Road to St Paul's, offers extraordinary insight into the artist and the two altarpieces.