Roman Catholic cardinals pray for divine intervention, hours before beginning a conclave to elect a new pope.
The Church is facing one of its most difficult periods in history, with a slew of sex scandals and rapidly dwindling popularity.
The cardinals, including the 115 aged under 80 who will vote for the next pontiff, are praying that God will inspire them to choose the right man.
This mass is the last event for the cardinals before they were to enter the Sistine Chapel on Tuesday afternoon for the conclave.
Vatican insiders say Italy's Angelo Scola and Brazil's Odilo Scherer have emerged as the men to beat.
The former would bring the papacy back to Italy for the first time in 35 years, while the latter would be the first non-European pope in 1,300 years.