Billie Bradley at Twin Lakes by Janet D. Wheeler

Billie Bradley and her brother and their closest friends decide to summer in two rented cottages at Twin lakes, a small resort community. There they find both fun and adventure as well solve the mystery of a young girl's lost history. This is the fifth entry in the Billie Bradley series. (Summary by KevinS)

Janet D. Wheeler is a pen name used by the Stratemeyer Syndicate for the Billie Bradley series.