"The Likeness" is a mystery novel by author Tana French, part of the Dublin Murder Squad series. The story follows detective Cassie Maddox, who goes undercover to investigate the murder of a woman who looks exactly like her. Cassie assumes the victim's identity, which leads her into a complex web of relationships and secrets among a group of friends. As Cassie delves deeper into the investigation, she grapples with her own identity and the emotional toll of living as someone else. The novel explores themes of friendship, deception, and the search for self, all set against the backdrop of Ireland.