Ralph Fiennes on choosing acting roles: "I like characters that have contradictions inside them"

In the new film "Conclave," based on the Robert Harris novel, Ralph Fiennes is a Vatican insider, the cardinal tasked with running the gathering of the entire College of Cardinals in Rome to select a new pope.

The film is partially set in the Sistine Chapel, literally "the room where it happens" when the election of a pope is concerned. But as imagined in the film, not serene.

"Conclave," which also Stanley Tucci, John Lithgow and Isabella Rosselini, is a taut thriller with a shock of an ending you just don't see coming. Fiennes, as Cardinal Thomas Lawrence, navigates the intrigue, the treachery even, of papal politics – a reluctant player consumed with doubt. As he tells the collected cardinals, "If there was only certainty and no doubt, there would be no mystery, and therefore no need for faith."