Gifted Girls. Daring Dames. Marvelous Mysteries. The Secret Spy Society is back with a new case to solve!

Peggy, Rita, and Dot are back in business! After officially naming themselves the Petite Private Eyes, they are ready to take on a new assignment from the Lady Spies. The Cat-Eye Twins, two local seamstresses, have had couture dresses stolen from their shop, and the girls will need to go undercover to find the culprit.

Good thing Sarah Edmonds (a Union Army spy who was known for dressing like a man to fight in the Civil War) is part of the Secret Spy Society and can help the girls come up with an ingenius disguise. But little do the girls know there is a larger mystery afoot . . .