Father Samuel Harbinger says goodbye to his friends and pet lion, Banda. As pastor of the remote Kenyan village of Lipoppo, he has been called to Rome to become a bishop and almost from the first moment that he steps off the plane in Rome, he is embroiled in controversy. He dances with an irate Pope, lends his cassock to a woman so she can satisfy the dress requirements for entrance to Saint Peter's Cathedral, and argues with conservative Cardinal Martin Jensen over allowing animals at mass. He shocks the Vatican by describing the governance of the Catholic Church as one of co-popes, the laity and the Holy Father. But, the controversy that surrounds Harbinger is not limited to the Catholic Church. He wins the Nobel Peace Prize, addresses the general assembly of the United Nations, and receives an honorary degree from Harvard University.
When the Pope suddenly dies, the College of Cardinals gathers in Rome to choose his successor. With Bishop Harbinger back in Rome, controversy enters once again, as those in the Sistine Chapel convene to elect the new Pope.