Goa, May 8 -- A plume of black smoke billowed over St. Peter's Square on Wednesday evening, signaling that the first round of voting in the papal conclave had failed to produce a two-thirds majority needed to elect a successor to the late Pope Francis. The symbolic smoke, generated from burning ballots inside the Vatican's Sistine Chapel, dashed hopes of a swift decision and left tens of thousands of gathered pilgrims and onlookers awaiting further news.

As the Catholic world turned its attention back to the Vatican on Thursday, 133 cardinals-referred to as the "Princes of the Church"-prepared for a second day of voting. After spending the night in seclusion at the Santa Marta guesthouse, the electors attended a private mass to seek divi...