Pope Benedict XVI has officially retired.
Thursday afternoon, the 85-year-old pontiff left the Vatican by helicopter to the papal retreat, flying over St. Peter's Square before he left.
He is the first pontiff in 600 years to resign from the post as the leader of the Roman Catholic Church.
Now, all eyes are on Rome as the time begins to elect a new pope.
Catholic or not, the process is fascinating, rooted in ritual, faith and history.
The conclave is something that novels and conspiracy theories are based on.
In simple terms, the conclave involves the cardinals gathering for a secret meeting in secret chambers for a secret vote.
"In the actual conclave, it is very similar to a religious ritual," said Leo Madden, theology professor at Ohio Dominican University.
For history buffs and anyone who appreciates the grand rituals of conclave, it's quite stunning how little has changed over the centuries.
The cardinals are called to the Sistine Chapel, and are then disconnected from the world.
"The doors are closed and there is no one else in the room except those cardinals who are eligible to vote. The room is swept clean of any listening devices, cell phone, electronic communication device," said Madden.
There are also strict rules from where the cardinals sit, to how they vote.
"Strict rules about how they will fill out their ballots, how those ballots will be delivered, read and given. The scene is very quiet. The cardinals carry out their tasks very slowly and carefully," Madden said.
Each casts a ballot, dropped in a chalice at the altar and then the votes are counted.
"If there has been two-thirds arrived at, then the ballots are immediately burned along with a special chemical that makes white smoke," Madden said.
If not, then black smoke emerges.
But even then, the Vatican can keep the world guessing.
In 2005, it was hard to know if the smoke was white or gray.
White smoke and bells together signal that a new pope has been selected to lead the Catholic Church.