Pope Benedict made history when he announced his resignation, becoming the first Pope to step down voluntarily in 600 years. In his wake he left a bitterly divided Vatican mired in scandals. But is Benedict's successor, Pope Francis, taming the forces that helped destroy Benedict's papacy? Is he succeeding in lifting the Church out of crisis? Nearly a year in the making, this film goes inside the Vatican -- one of the world's most revered and mysterious institutions -- to unravel the remarkable series of events that led to the resignation that shook the world. Through interviews with those at the very heart of what happened -- cardinals, priests, convicted criminals, police, prosecutors and whistle-blowers -- FRONTLINE gives a first-hand account of the final days of Benedict's papacy and the current battle to set the Church on a new path under Francis.