The papal conclave is a succession drama like no other. Triggered by the death of Pope Francis, 133 cardinals descend on the Vatican to elect his successor. But these cardinals are not just electors - they are candidates too. One of these 133 men will become pope. It is an ancient ritual of prayer and isolation that determines the future of the Catholic Church - and it all unfolds in secrecy. With unprecedented access to the Vatican, this documentary offers a rare insight into a ceremony that has decided the church’s leadership for centuries, featuring a glimpse of what happened inside that is told by those who were there.