Chosen to attend a reenactment of North against South at Gettysburg National Military Park, Ben and Bekka Cooper, along with their classmates experience a once-in-a-lifetime field trip. Putting their keen eyes and quick thinking to the test, they uncover a plot to ruin the event. With the help of a camera, travel book, and a secret weapon, the spies in disguise did not get away with the crime.

Spies in Disguise at Gettysburg gives young readers what they've come to expect from Mary Morgan--a book of mystery they can take to the park and live out. Add it to Stolen Treasures at Pictured Rocks and The Face at Mount Rushmore, then follow them as they cross the country on their next National Park adventure.