Who's That Girl? is an intriguing mystery thriller written by Tana French. The book follows the story of Detective Cassie Maddox, who is assigned to investigate the murder of a young woman who bears an uncanny resemblance to her. As Cassie delves deeper into the case, she uncovers a complex web of secrets and lies that lead her to question her own identity. With its atmospheric setting and gripping plot, Who's That Girl? is a gripping page-turner that will keep you guessing until the final twist.