Chapel and lock the doors behind them, technicians will have pulled up the floor boards to install cell phone jamming devices. violating the secrecy is punishable by excommunication. >> it's a way of ensuring that the voice that's speaking to the cardinals during the conclave belongs to the holy spirit and no one else. >> reporter: no one knows how long it will take. the shortest conclave lasted just a few hours. the longest, nearly three years. in fact, that's why they started locking the doors. in the middle ages during the plague years, a conclave meeting in the town of beterbo took so long...