Title: Trouble at the Treasury (Capital Mysteries #7)
Description: Children's mystery story. Seventh in the Capital Mysteries series featuring "First Daughter" KC Corcoran and her best friend Marshall Li. 

After taking a tour of the National Bureau of Printing and Engraving, KC and Marshall find out from KC's stepdad, the President of the United States, that several stacks of $100 bills have gone missing. KC is determined to track down the thieves.
Subjects: Money, United States. Bureau of Engraving and Printing, Fiction, United States, Stealing, Mystery and detective stories, Juvenile fiction, United States. Department of the Treasury, Theft