For twenty-seven years, Y/N Taylor believed one thing above all else—her father never knew she existed. After her mother’s death, a box of forgotten letters and a faded photograph lead her to a single name: Mac Taylor, Director of the New York Crime Lab. Expecting nothing more than answers, Y/N travels to New York to meet the man she’s spent her entire life wondering about. Instead, she changes both of their lives forever. As Mac struggles to come to terms with the daughter he never had the chance to raise, he discovers that Y/N has already built an extraordinary life of her own as a respected Crime Scene Investigator with the Chicago Crime Lab. While father and daughter slowly learn to become the family they were denied for twenty-seven years, a joint investigation between Chicago and New York reveals just how naturally Y/N belongs among Mac’s team. Surrounded by Stella, Danny, Lindsay, Hawkes, Adam, Sid, and Detective Don Flack, she finds herself becoming part of a family she never expected to have. But as Y/N considers leaving Chicago for a new beginning in New York, she must balance the career she’s worked so hard to build, the father she’s only just found, and the unexpected connection growing between herself and Detective Don Flack. In a city built on secrets, the greatest mystery Mac Taylor will ever solve isn’t a murder—it’s how to be a father to the daughter he never knew he had.