The Burden of Darkness is the fifth in The Marcie Kane Thriller Collection. Although part of a series, The Burden of Darkness stands alone. Like the other books in the collection, this one tackles a subject of social significance. Marcie Kane’s FBI consultant husband, Nathan Harris, is battle weary and suffering from PTSD from previous cases. He eventually seeks counseling with the help of Marcie, but is it too late? He has everything to gain by trying.