This is probably a viable option only for Catholics or persons actually interested in The Church, and even then "of limited audience", but when Pope Francis said that he had a favorite novel, had read it three times already and was looking forward to a fourth, {because "Manzoni has given me so much"}, I bought an old version of Manzoni's THE BETHROTHED, written in the 1840s.
It's considered one of the masterpieces of Italian literature, but I find it a clever but tough read. It DOES however seem to give me some depth insight into Pope Francis, due to the way the author handles the three priests involved, and approaches certain moral situations regarding the poor and the young and the powerful-abusing-power.
...NOT however a car-chase, explosion-a-minute, page turner.