Sophie discovers a mysterious crystal cave, but her friends don't believe her, in this twelfth charming book of The Adventures of Sophie Mouse series! Sophie Mouse and her friends are playing hide-and-seek near Butterfly Brook. Sophie finds the perfect hiding spot, but she finds something else, too! It's a glowing cave. The problem is, when Sophie tells her friends about her discovery, they don't believe her! After all, who's ever heard of a cave that glows? Now Sophie is on a mission to prove she's telling the truth! With easy-to-read language and illustrations on almost every page, the Adventures of Sophie Mouse chapter books are perfect for beginning readers.