As a fireworks expert tests the Vatican's contemporary system for "holy smoke," Catholic cardinals mull their divergent priorities for Pope Francis' successor.

The Catholic Church will begin the secretive process to elect a new pope on Wednesday. The cardinals eligible to vote will surrender their phones and be barred from outside contact during the conclave.

Conclave” the film may have introduced moviegoers to the spectacular ritual and drama of a modern conclave, but the periodic voting to elect a new pope has been going on for centuries and created a whole genre of historical trivia.