Each time a new pope is elected, the world holds its breath, watching for smoke from the roof of the Sistine Chapel: black smoke indicates that a ballot has not resulted in any candidate winning a two-thirds majority, whereas white smoke is the signal that a new pontiff has been elected. The smoke itself is a relatively recent tradition, but the practice of locking the cardinal-electors in a conclave goes back centuries. The outside world is not supposed to know what happens inside conclaves, but it is possible to piece together enough information to create a history, and that history can explain what happens in modern papal elections. The subject matter can be adapted to suit a variety of audiences, who can ask for talks of varying lengths or with emphasis on particular periods of history. There is considerable scope for anecdotes, as well as for comparing and contrasting real conclaves with fictional versions of what might or might not happen behind locked doors.