Transcript for Behind the Scenes of the Papal Conclave
the world's eyes, inside the walls of the sistine chapel. Tonight, crews have installed that famous chimney, the smoke will reveal a lot. Black smoke means no compromise. White smoke means at least two-thirds agreed on the new pope. Reading those signals hasn't always been easy. Reporter: Today, a pair of firefighters gingerly climbed on the roof of the sistine chapel installing the chimney the whole world will be watching. Delg kate work considering the ceiling below is the michelangelo's masterpiece. Are they eager to get going? It depends on which cardinal that you talk to. Repor ALL INDICATIONS Are they're not close to reaching a consensus. The two factions are the roman party and the reform party. Reporter: One side, roman insiders who reportedly drafted a brazilian as their front runner. The archbishop of san paolo. The roman curia seems to like him, the argument against him for the reformers. Reporter: The reformers led by the u.S. Delegation want a sheriff to clean house. Possibly even an american. Starting tuesday, the cardinals shut out the chatter, praying and voting, burning the ballots behind closed doors. Leaving us to interpret the smoke signals. And it looks again as if we're getting black smoke. Reporter: But in 2005, it was tough to tell. Even for those of us watching right here in st. Peter's square. A bit whiter than the previous smoke. People are cheering. They're moving forward. Reporter: Nearly five minutes ticked by of delicious uncertainty. That is white smoke. Reporter: It sure does look white at the moment. Today, the vatican spokesman admitted that he wasn't sure that day and he was asked if this time around he might send out an e-mail to clarify the situation. Today, he said, absolutely not, the suspense is part of the mystery.
This transcript has been automatically generated and may not be 100% accurate.