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.

The oath-taking is being held in the Pauline Chapel at the Vatican for all those assigned to the upcoming conclave. They include clerics in support roles, including confessors speaking various languages. The cardinals themselves will take their oath on Wednesday in the Sistine Chapel, before they cast their first ballots.

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

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

The 2025 conclave is less predictable than ever after Francis shook up the Catholic Church during his years as pope. More Catholic Church cardinals will move into the Sistine Chapel in the Vatican on May 7 than for any papal election to date: 133 cardinals are expected.