When Cass begins to hear voices while backpacking with her husband Gav through former Yugoslavia, she attributes it to travel stress and cracks appearing in her new marriage. However, when the couple embarks on an unplanned sight seeing expedition with a mysterious local named Saint Peter, Cass quickly suspects that his promises to give them an "authentic" tour of his homeland conceal a much darker purpose. When Gav goes missing, Cass soon finds herself dragged into an increasingly paranoid web of manipulation and murder from which even death offers no escape.