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The white smoke is famous. When it streams out of a chimney at the Sistine Chapel, it signals that a new pope has been chosen and sets off celebrations among some 1.4 billion Catholics around the world.
Behind the scenes, a mysterious and intensely dramatic process culminates in that smoke — literally. It's created by burning the ballots cardinals just used. White smoke signals that the Roman Catholic Church has a new leader; black smoke means the cardinals will need to vote again.
With the death of Pope Francis, the elaborate mechanism will now begin to decide who sits in power at the Vatican, the seat of the last absolute monarchy in Europe. It centers around the conclave, a gathering whose name stems from the Latin for "with key."
"That actually comes from the 13th century," Bry Jensen, host of the long-running Pontifacts podcast, tells NPR. She says cardinals couldn't agree on a new pope in 1268 and the Church went nearly three years without a pontiff, despite growing frustration outside the cardinals' ranks.
"They locked the cardinals up behind closed doors, and then they put them on water and bread so that they would focus on the essentials," says Kurt Martens, ordinary professor of Canon law at the School of Canon Law at the Catholic University of America.
That initial conclave elected an archdeacon who was not an ordained priest, who became Pope Gregory X. The new pope ordered that future Church transitions would begin with a conclave, to avoid long vacancies.
Cardinals in the conclave will be locked away within the Vatican, cut off from the outside world. As they deliberate, news outlets point cameras at the chapel's chimney, and arcane words enter casual conversation, like Papabili, or "pope-able," the term for cardinals with a chance of becoming pope.
Pontiff's death triggers a unique process
When a reigning pope dies, an immediate duty falls to the camerlengo, a cardinal whose title translates to "chamberlain." The camerlengo declares the pope is deceased and administers the Holy See until a successor is chosen. The current camerlengo is Cardinal Kevin Farrell, the first American in that post.
You might have heard that the camerlengo uses a silver hammer to tap a pope's forehead three times, to ascertain whether he's alive. The practice has become a matter of legend, Martens says.
"The last time that that ritual was used was in 1878 when Pius IX died," he says, "but that's not done anymore."
Funeral rites for the late pope are held for nine days, as he is mourned and celebrated. Conclaves must begin within 15 to 20 days after a pope dies or resigns.
Upon the pope's death, the dean of the College of Cardinals calls the cardinal electors to the Vatican. There are currently 138 of them. To join the conclave, cardinals must be under 80 years old.
During the conclave, the cardinals live in the Domus Sanctae Marthae, a hotel-like facility next to St. Peter's Basilica. It's where Pope Francis opted to live, rather than in the Apostolic Palace's papal apartments. The residence has been compared to a three-star hotel.
"I've eaten there. I must say I'd rather go to a nice Roman restaurant than eat there," Martens says. But, he adds, that's part of the point.
"You don't want to make it more than a three-star hotel. Because you don't want the Cardinals to get comfortable," but instead to focus on electing a pontiff.
Conclave begins with oaths of secrecy
The rituals take place according to rules popes have refined over the centuries, clarifying the timeframe and obligations. But the conclave itself must be obscured by "total secrecy," as Pope John Paul II wrote. Cardinal electors must sign an oath of secrecy and seclusion, under threat of excommunication.
That's why the process intrigues so many people, says Gregg Gassman, a librarian who edits the Pontifacts podcast.
"Some of the mystery does come from the closed nature of the conclave itself," he says. "It's fascinating."
Once the cardinals are gathered, the dean of of the College of Cardinals presides over a mass. The group then walks together from the Pauline Chapel to the Sistine Chapel, singing hymns invoking the Holy Spirit.
In the Sistine Chapel, the conclave swears a secrecy oath in Latin, touching the Holy Gospels.
"When that ceremony is over, you have the papal master of ceremonies who in a dramatic way says, Extra omnes," Martens says. "Roughly, it means, 'Get the hell out of here, all you who don't belong here,' meaning only the cardinal electors can remain."
Outside the chapel, the famed Papal Swiss Guard stands guard.
"That's when the doors are locked, that's when the verbal and communicative gates go down," Jensen says. "After Extra omnes, there is no further communication until a pope has been elected, aside from smoke."
The conclave begins voting
"There's only one round that first evening, and then you will see black smoke or white smoke," Martens says.
Typically, he says, the first round is merely an indication of the cardinals' priorities. On the following day, the conclave starts holding two rounds of voting each morning, and another two in the afternoon.
After each vote, a needle is pushed through the ballots, binding them together. If no winner emerges with a two-thirds majority, the two packages are "put together in that stove that is in the corner of the Sistine Chapel, to burn them and produce whatever smoke needs to be produced — white or black," Martens says.
The Church once used wet straw or dry straw to produce the right color, but to avoid confusion, the process now relies on chemicals.
The cardinals will continue to pray and contemplate — and vote — until a new pope is elected.
How long do conclaves last?
"All of the conclaves from the 1900s onwards have been under four days," Jensen says.
Francis was elected pope on the conclave's second day, for instance.
After a successful vote, the winning candidate is asked two questions. The first is whether they accept their election as pope.
"And then the second question is going to be, 'What name do you choose?' And then the name is chosen," Martens says.
Before Pope Francis was elected, many of the faithful in Buenos Aires knew their archbishop as simply "Father Jorge," as NPR reported in 2013.
Official documents are filled out, and the new pope is taken into a sacristy, to be fitted with papal attire.
"There are typically three sets of vestments ready," in sizes roughly equal to small, medium and large, Martens says.
Soon afterward, the senior cardinal deacon will appear on the balcony over St. Peter's Square, announcing, Habemus Papam! — "We have a pope!"
It will then be the new pope's turn to emerge onto the balcony and deliver his first blessing.
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