When OWCA creates a new branch for teenage spies, Fireside Girl Troop 46231 catches their eye. Old friends Major Monogram and Eliza Feyersied train the, now older, girls to be some of the best spies in history, under the guise of a summer camp. When a new, surprising villain takes Danville, the girls struggle with test of trust, love, and everything they have come to stand for.