Arcana the Book

"En route to Italy, a group of American tourists learn of a series of DIY travel guides, nicknamed 'The Book.' These unofficial guides are collected and updated with first-hand experience by the travelers themselves. A local cult, practitioners of Sanctus Letum, the Holy Death, disrupts the American's plans for adventure when they hide pages from the Dark Book, Shaitan, in one of the travel guides. The friends are lead down a path of secret religion, death, resurrection, and demonology."