The Secret of the Old Clock
The first of many, many mysteries I would come to read in this highly addictive series published under the pseudonym of Carolyn Keene. This is one of the all-time bestselling children's books in English: it's sold nearly 3 million copies. The writing may not hold up on an adult's re-read, but I love the Nancy Drew series anyway: she's smart, she's brave, and she's the one rescuing her boyfriend, instead of the other way around.
Publisher’s description:
Nancy Drew’s keen mind is tested when she searches for a missing will.