Sixth-grader Ruth Mudd-Flaherty hasn't yet found her place at Humberboldt Middle School, at least that's how her moms see it. She prefers to be a lone wolf now that her very best friend, Charlotte Diamond, has moved on to a new, more socially acceptable group of friends. Ruth has been spending most of her time at the public library studying words for their school's upcoming spelling bee. She just knows that winning the bee will make people see her differently. Until she finds a mysterious note tucked into an old book...and in that note is a riddle.
With no choice but to accept this mysterious invitation, Ruth sets off on a quest that could provide the answers to all her questions. But when solving the riddles becomes too difficult to complete alone, Ruth must allow others in. And doing so means that she might just end up making a new set of friends who share her love of adventure.