"Betty Gordon at Mountain Camp; Or, The Mystery of Ida Bellethorne" by Alice B. Emerson is a novel aimed at young readers, likely written during the early 20th century. This book follows the adventurous and curious young protagonist, Betty Gordon, as she navigates a new chapter in her life filled with friendships, challenges, and the unraveling of a mystery concerning a girl named Ida Bellethorne. The opening of the story introduces Betty as she wanders through an old-fashioned neighborhood while shopping, where she encounters a delightful orange silk blouse in a quaint shop. Here, she meets Ida Bellethorne, an English girl working in the store who seems to harbor secrets of her own. When Betty buys the blouse, she unwittingly drops a precious locket given to her by her guardian, Uncle Dick. As Betty prepares for a trip to Mountain Camp with friends and learns about the mysterious connection between her locket and Ida, the stage is set for a tale of discovery and adventure, meant to engage readers in the charm and excitement of Betty's world while hinting at deeper mysteries yet to unfold. (This is an automatically generated summary.)