For their run up to Printer’s Row Lit Fest in Chicago, the Chicago Tribune has been profiling writers who will be attending to promote their recent work. Cristina Henríquez is a Chicago-area fiction writer and author of the new novel “The Book of Unknown Americans.” When discussing the subject of immigration, the conversation can quickly become very heated along partisan lines. Henríquez wrote a book to do just the opposite - to the tell the quiet, human side of immigration.