Christina, who has a knack for stumbling upon (and solving) real-life mysteries, heads to Savannah, GA, where she and her Girl Scout friends are eager to join in the festivities for the National Camporee celebrating the Girl Scouts' 100th Anniversary. Although they are staying with Mimi, Christina's mystery-writing grandmother, Christina reassures the girls that on this trip, there will be no funny business and no mysteries.

But as they begin exploring the historic city, they discover that someone is leaving creepy clues that lead them to River Street, a spooky cemetery, on a ghost tour, and even to Juliette Gordon Low's home. Soon, they find themselves in the middle of a real mystery that is going to need all the Scouting skills they have, as well as their friendship, to work out! With just a few days until the Camporee begins, the girls put their skills into action to solve a mystery filled with giggles, goose bumps and “s'more!”