Workers and clerics assisting the dozens of Catholic cardinals set to gather Wednesday to begin voting on the next pope had to swear to never reveal anything about the proceedings or else risk the Church’s gravest punishment: religious banishment. The employees took their oaths in the Papal Chapel.

All Vatican personnel involved in supporting the upcoming papal conclave will take an oath of secrecy — under penalty of automatic excommunication.

Dozens of Vatican staff members, including security, housekeeping and maintenance workers, are sworn to secrecy regarding anything they witness during the upcoming papal conclave.

A papal conclave is set to begin in Vatican City starting May 7, during which cardinals from around the world will elect the next leader of the Roman Catholic church. The tradition occurs any time a pope dies or resigns from the office. Pope Francis died April 21, the day after Easter.

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