Great girl gumshoe, Daisy Diamond, and her best friend, girl scientist, Sally Sosmart, are off on their first novel-length adventure. This time a note left in a book owned by Sally’s late Aunt Melvinia leads them to her mansion in search of a priceless artifact. The only problem is, all of Aunt Melvinia’s belongings are about to go up for auction the following day. So not only are the girls in a race against time, but they soon learn they’re not the only ones looking for Aunt Melvinia’s most prized possession. Of course, it doesn’t help that a thunder storm rages outside, especially when the girls discover the mansion is riddled with secret passageways … Holy Cannoli!