Robert Harris novel "Conclave" and screening adaptation is story about this: The pope is dead. Behind the locked doors of the Sistine Chapel, one hundred and eighteen cardinals from all over the globe will gather to cast their votes in the world's most secretive election. They are holy men. But they are not immune to the human temptations of power and glory. And they are not above the tribalism and factionalism that consumes humanity. When all is said and done, one of them will become the most powerful spiritual figure on Earth.

https://www.fantasticfiction.com/h/robert-harris/conclave.htm