Written by a pair of authors who go under the name Karen Perry, “Girl Unknown” is set in Ireland. David and Caroline are a married couple with 2 children. One day a young woman tells David she is his daughter from a former relationship before he was married. Their lives are upended by this news and the scarring behavior of this new member of their family. Caroline is hesitant to open her home to this stranger. David feels guilt and anticipation along with memories of the long ago romance with the girl’s mother. However, is this girl as innocent as she seems? What are her true objectives in seeking David out at this time in her life? Told from alternate perspectives with an unexpected, twist ending, “Girl Unknown” is an entertaining thriller.