The story is set in the wake of 2 April 2005, when the death of Pope John Paul II sent shockwaves across the Catholic world. The story follows US-born Father Joseph Murolo (Ruffalo), summoned by the Vatican to lead the investigation into the pontiff’s life. As devil’s advocate, Murolo must make sure that nothing undermines the sanctification of Karol Wojtyla, the first non-Italian pope in 450 years. As he interviews a range of witnesses – ranging from devoted colleagues to secret confidants – Murolo is drawn ever deeper into a moral labyrinth. This journey of truth will ultimately put his own faith to the test.