The Secret of the Old Clock is a cozy antique mystery book written by Carolyn Keene. This beloved novel is the first installment in the Nancy Drew series, which has captivated readers for decades. Join Nancy Drew, a young amateur detective, as she embarks on a thrilling adventure to uncover the secret behind an old clock. With its nostalgic charm, clever puzzles, and engaging storytelling, this book is perfect for those who enjoy cozy mysteries with a vintage twist.