The Secret of the Old Clock is a cozy antique mystery book written by Carolyn Keene. This classic novel follows the adventures of Nancy Drew, a young detective with a knack for solving mysteries. In this particular story, Nancy stumbles upon an old clock that holds a secret. As she delves deeper into the mystery, she uncovers a hidden treasure and unravels a decades-old family secret. With its charming antique setting and intriguing plot, The Secret of the Old Clock is a must-read for fans of cozy mysteries and antique enthusiasts.