Javier Cercas describes his book as a non-fiction novel about Pope Francis, highlighting the unprecedented access he had to the Vatican. Despite being an atheist, he accepted the commission as a unique opportunity. Cercas discusses the complexities of Pope Francis's role, emphasizing that while he raises important issues, the Church's change is slow. He believes the next pope will continue Francis's reforms but with moderation. Cercas also explores theological questions, particularly concerning life after death, which he leaves unanswered until the end of his book.